Cardiac Sarcoidosis

Table of Contents

  1. Overview
  2. Epidemiology
  3. Pathophysiology and Granuloma Formation
  4. Cardiac Manifestations
  5. Diagnosis and HRS Criteria
  6. Cardiac MRI and FDG-PET
  7. Arrhythmia and Sudden Death Risk
  8. Treatment
  9. Device Therapy — ICD and CRT
  10. Monitoring and Follow-up
  11. Prognosis
  12. Research Papers
  13. Connections
  14. Featured Videos

Back to Table of Contents

1. Overview

Cardiac sarcoidosis (CS) is a granulomatous infiltration of the myocardium by non-caseating granulomas. Sarcoidosis itself is a multisystem inflammatory disease of unknown etiology, capable of affecting virtually any organ, but most commonly the lungs, lymph nodes, skin, and eyes. Cardiac involvement is clinically apparent in approximately 5% of patients with systemic sarcoidosis, yet autopsy series consistently reveal subclinical cardiac involvement in 20–25% of patients with known systemic disease — and in up to 50% of Japanese autopsy series. This striking discrepancy highlights CS as a profoundly underdiagnosed condition.

CS is an important and under-recognized cause of atrioventricular (AV) block, ventricular tachycardia (VT), and heart failure in patients aged 20–60 years. A critically important clinical point: many patients present with cardiac symptoms as the first or only manifestation of sarcoidosis, without any known history of pulmonary or systemic sarcoidosis. When a middle-aged patient develops otherwise unexplained complete heart block, ventricular tachycardia, or dilated cardiomyopathy, cardiac sarcoidosis must be on the differential diagnosis even without a preceding sarcoidosis diagnosis.

The hallmark pathology of CS is the epithelioid granuloma: a tightly organized cluster of activated macrophages (epithelioid histiocytes) surrounded by Langhans multinucleated giant cells, CD4+ T lymphocytes, and a peripheral rim of fibroblasts. These granulomas are described as non-caseating — unlike the caseating (necrotic, cheese-like) granulomas of tuberculosis, sarcoid granulomas do not undergo central necrosis. Over time, these granulomas replace normal myocardial architecture, and as they heal they leave behind fibrosis and fatty infiltration. This replacement of organized myocardium with fibro-fatty scar creates the substrate for both conduction system disease and malignant ventricular arrhythmias.

CS represents a disease at the intersection of cardiology, electrophysiology, rheumatology, and pulmonology. Optimal management requires a coordinated multidisciplinary approach combining accurate diagnosis, immunosuppressive therapy to arrest active inflammation, and device-based protection against sudden cardiac death. Early recognition and treatment can reverse conduction disease, improve left ventricular ejection fraction, and reduce arrhythmia burden — but delayed diagnosis significantly worsens outcomes.

Back to Table of Contents

2. Epidemiology

Systemic sarcoidosis has an estimated incidence of 10–35 per 100,000 in the United States. African Americans are disproportionately affected, with an incidence approximately three times higher than in White Americans and a tendency toward more severe, multisystem disease. Women are slightly more commonly affected than men. The peak age of onset is 25–45 years, though a second smaller peak occurs in women over 50. Sarcoidosis is a global disease, but prevalence varies considerably by geography and ethnicity — notably high in Scandinavia and among African Americans.

Cardiac sarcoidosis specifically:

The combination of under-recognition, variable presentation, and potentially lethal arrhythmias makes epidemiological vigilance essential. Clinicians evaluating unexplained cardiomyopathy, heart block, or ventricular tachycardia in a patient between ages 20 and 60 should maintain a low threshold for pursuing a CS workup.

Back to Table of Contents

3. Pathophysiology and Granuloma Formation

Etiology of sarcoidosis remains incompletely understood. The prevailing hypothesis is an abnormal, exaggerated Th1-mediated immune response to one or more poorly cleared antigenic stimuli in genetically susceptible individuals. Candidate antigens include mycobacterial proteins (particularly Mycobacterium tuberculosis catalase-peroxidase), Propionibacterium acnes (an anaerobic skin commensal found in sarcoid granulomas), and various organic dusts and inorganic particles. None has been definitively proven as the universal causative antigen. HLA class II alleles (especially HLA-DRB1) influence susceptibility and phenotype.

Granuloma formation and cardiac tropism: In the heart, granulomas do not distribute uniformly. They preferentially affect the basal interventricular septum — the anatomical location of the AV node, His bundle, and proximal bundle branches. This preferential involvement directly explains why AV block and bundle branch block are so characteristic of CS: the granulomas physically infiltrate and disrupt the specialized conduction tissue. The left ventricular free wall is the second most commonly involved region. The right ventricle, atria, and valvular apparatus can also be affected but less commonly.

Three pathological stages of cardiac sarcoidosis:

  1. Active granulomatous inflammation: Epithelioid granulomas are metabolically active, taking up fluorodeoxyglucose (FDG) on PET imaging. This stage is most responsive to corticosteroid therapy. Inflammation may cause myocardial edema, conduction system dysfunction, and direct cardiomyocyte injury. Importantly, at this stage, the process may be largely reversible.
  2. Healing phase: Active granulomas are replaced by fibrosis and fatty infiltration. The transition from active inflammation to fibrosis marks the beginning of irreversibility. Some patients cycle between active and healing phases, particularly if immunosuppression is inadequate or withdrawn prematurely.
  3. Scarring (end-stage fibrosis): Permanent transmural or patchy myocardial fibrosis with fatty replacement. This stage is characterized by irreversible LV dysfunction and — critically — creation of a permanent ventricular tachycardia substrate. Reentrant VT circuits form at the interface between viable myocardium and the fibrotic/fatty scar, where slow conduction zones enable electrical reentry.

Why endomyocardial biopsy has low yield: The patchy, non-uniform distribution of sarcoid granulomas means that a standard endomyocardial biopsy (which samples only a few milligrams of right ventricular septal endocardium) misses the granulomas approximately 70–80% of the time. Even electroanatomic-mapping-guided biopsy targeting areas of abnormal electrical signal improves but does not normalize yield. This limitation means that a negative biopsy does not exclude CS, and the 2014 HRS criteria appropriately allow clinical diagnosis of CS based on extracardiac histology plus supportive cardiac findings.

Molecular mechanisms of granuloma-mediated arrhythmogenesis: Granuloma macrophages and activated T cells secrete TNF-alpha, IL-12, IL-18, and IFN-gamma in a self-amplifying Th1 loop. Angiotensin-converting enzyme (ACE) is produced by granuloma macrophages, which is why serum ACE is elevated in active systemic sarcoidosis. However, serum ACE is neither sensitive nor specific for cardiac involvement specifically — it reflects total granuloma burden, not cardiac burden. The fibro-fatty replacement of myocardium creates zones of heterogeneous electrical conduction: areas of very slow conduction surrounded by normal myocardium create the classical conditions for re-entrant ventricular tachycardia, analogous to the post-MI scar-mediated VT mechanism but with a characteristically different distribution (basal septal and lateral, rather than coronary territory-based).

Back to Table of Contents

4. Cardiac Manifestations

Cardiac sarcoidosis can manifest across a broad spectrum of presentations, from incidentally discovered subclinical findings to catastrophic sudden cardiac death. The principal clinical syndromes are:

Atrioventricular and Conduction System Disease

The most common initial presentation of CS, occurring in 23–30% of patients at diagnosis. The spectrum ranges from first-degree AV block (PR prolongation) through second-degree AV block (Mobitz I or II) to complete (third-degree) AV block with junctional or ventricular escape rhythm. His-Purkinje disease also occurs: right bundle branch block, left bundle branch block, and bifascicular block (RBBB + left anterior or posterior fascicular block) are all recognized manifestations of CS. Any unexplained high-grade AV block in a patient under 60 should prompt evaluation for CS, even in the absence of other sarcoidosis features. Conduction disease in CS has a characteristic feature of being potentially reversible with corticosteroid therapy — though permanent pacing or ICD is still usually required as a bridge and often permanently.

Ventricular Arrhythmias

CS is a substrate for severe ventricular arrhythmias. Non-sustained VT (NSVT) is common on Holter monitoring. Sustained monomorphic VT results from scar-mediated reentry in the basal septum and lateral wall. The VT morphology is often a left bundle branch block (LBBB) pattern with superior axis, consistent with a right-sided or septal exit point. Ventricular fibrillation and sudden cardiac death can be the presenting manifestation of CS, occurring before the diagnosis is established. VT storm (multiple hemodynamically destabilizing VT episodes within 24 hours) is a recognized, life-threatening complication. The combination of conduction disease and ventricular tachycardia in the same patient is particularly characteristic of CS — a combination less common in most other cardiomyopathies.

Heart Failure and Cardiomyopathy

Granulomatous replacement of myocardium, followed by fibrosis and fatty infiltration, leads to progressive LV dysfunction. CS can present as a dilated cardiomyopathy pattern (LV dilation with reduced ejection fraction), a restrictive pattern (impaired diastolic filling with preserved or mildly reduced EF, often with biatrial enlargement), or a mixed pattern. Basal septal thinning and hypokinesis — a region that is typically spared in coronary artery disease and unusual in other cardiomyopathies — is a useful echocardiographic clue to CS. CS can also mimic arrhythmogenic right ventricular cardiomyopathy (ARVC) when fatty replacement is prominent in the right ventricular free wall.

Pericardial Disease

Pericarditis and pericardial effusion occur in approximately 5% of CS patients. Effusions are typically exudative and may be hemorrhagic. Cardiac tamponade from CS is uncommon but reported. Constrictive pericarditis from sarcoid-related pericardial fibrosis is rare.

Valvular Disease

Papillary muscle involvement by granulomas can cause mitral regurgitation through papillary muscle dysfunction or rupture in severe cases. Tricuspid regurgitation may develop secondary to right ventricular pressure overload from pulmonary hypertension. Primary valvular sarcoid granulomas are uncommon.

Pulmonary Hypertension and Right Heart Failure

Pulmonary hypertension in sarcoidosis can arise from multiple mechanisms: extrinsic compression of pulmonary vessels by mediastinal granulomas, direct pulmonary vascular granulomatous infiltration, or secondary cor pulmonale from pulmonary fibrosis. Significant pulmonary hypertension leads to right ventricular pressure overload, RV hypertrophy, dilation, and eventually right-sided heart failure — a presentation that can dominate the clinical picture in advanced pulmonary sarcoidosis.

Back to Table of Contents

5. Diagnosis and 2014 HRS Criteria

The 2014 Heart Rhythm Society (HRS) Expert Consensus Statement on the Diagnosis and Management of Arrhythmias Associated with Cardiac Sarcoidosis provides the most widely adopted diagnostic framework. The criteria recognize two pathways to diagnosis:

Histological Diagnosis (Definitive)

Non-caseating granulomas identified on cardiac tissue from any of the following sources:

Clinical Diagnosis (Requires All of the Following)

  1. Histological diagnosis of extracardiac sarcoidosis — non-caseating granulomas on biopsy of accessible tissue: lung (transbronchial, VATS, or surgical), mediastinal lymph nodes (EBUS-guided), skin granulomas, conjunctival nodules, or any other site. This is the most important step — confirming systemic sarcoidosis makes cardiac involvement much more plausible.
  2. At least one of the following cardiac criteria:
    • Steroid-responsive cardiomyopathy or heart block (LVEF improvement or conduction normalization with corticosteroids)
    • Unexplained LVEF <40%
    • Unexplained sustained VT, high-degree AV block, or bundle branch block
    • Patchy myocardial uptake on radionuclide scan (Ga-67 or FDG-PET) consistent with granulomatous inflammation
    • Late gadolinium enhancement (LGE) on cardiac MRI in a pattern consistent with CS
  3. Other causes excluded: coronary artery disease, other cardiomyopathy, Lyme carditis (especially for AV block), giant cell myocarditis, and other infiltrative diseases.

Diagnostic Workup for Suspected CS

Important Mimics and Differential Diagnosis

Back to Table of Contents

6. Cardiac MRI and FDG-PET Imaging

Cardiac MRI (CMR)

CMR is the gold standard for tissue characterization in CS. Its ability to detect myocardial fibrosis, edema, and structural abnormalities with high spatial resolution makes it the single most informative non-invasive test for CS diagnosis and risk stratification.

Late gadolinium enhancement (LGE) in CS: Gadolinium chelate accumulates in areas of fibrosis and granuloma where normal membrane integrity is disrupted. The LGE pattern in CS is characteristic:

Advanced CMR mapping techniques: T2 mapping quantifies myocardial edema (elevated T2 signals active inflammation — potentially steroid-responsive). Native T1 mapping and extracellular volume (ECV) quantify fibrosis extent. These parametric mapping approaches can detect diffuse myocardial abnormality even in regions without focal LGE, and may identify early CS before overt structural disease develops.

Critical limitation of CMR: LGE cannot distinguish between active granuloma (FDG-PET positive, steroid-responsive, potentially reversible) and healed fibrotic scar (FDG-PET negative, steroid-resistant, permanent). Both produce LGE. For this reason, CMR and FDG-PET are complementary rather than interchangeable — CMR defines structural architecture and fibrosis extent, while FDG-PET defines inflammatory activity.

FDG-PET Imaging

18F-fluorodeoxyglucose (FDG) PET exploits the fact that metabolically active inflammatory cells — activated macrophages and granuloma epithelioid cells — have markedly upregulated glucose consumption. Active sarcoid granulomas avidly accumulate FDG, producing focal "hot spots" on PET imaging.

Patient preparation — critically important: Normal resting myocardium uses free fatty acids as its primary energy substrate. After a standard overnight fast, myocardial cells shift toward glucose utilization, creating diffuse myocardial FDG uptake that would obscure focal granuloma uptake. To suppress this background, patients must undergo:

PET/CT perfusion-FDG mismatch analysis: Rubidium-82 or N-13 ammonia perfusion PET performed immediately before FDG acquisition allows direct comparison:

Whole-body FDG-PET: A major advantage of FDG-PET over CMR is simultaneous whole-body assessment. Whole-body PET identifies extracardiac sarcoidosis (mediastinal/hilar lymphadenopathy, pulmonary granulomas, bone/muscle/skin involvement) that can be biopsied to confirm the diagnosis histologically, supporting a clinical CS diagnosis without requiring endomyocardial biopsy.

Treatment monitoring: Serial FDG-PET is the most sensitive tool for monitoring response to immunosuppression. Successful corticosteroid therapy should reduce or eliminate focal myocardial FDG uptake at repeat imaging (typically 3–6 months after initiating treatment). Persistent or worsening FDG uptake despite adequate steroid doses suggests treatment failure and the need for intensification or alternative immunosuppressive agents.

Gallium-67 (Ga-67) Scintigraphy

An older nuclear medicine technique that identifies inflammatory tissue by macrophage uptake. The "panda sign" (bilateral parotid and lacrimal gland uptake) combined with the "lambda sign" (bilateral hilar + right paratracheal lymph node uptake) on Ga-67 scanning is classic for systemic sarcoidosis. However, Ga-67 has substantially lower spatial resolution and sensitivity compared to FDG-PET and has been largely replaced by FDG-PET at centers where it is available. Ga-67 remains clinically used where FDG-PET is unavailable.

Back to Table of Contents

7. Arrhythmia and Sudden Cardiac Death Risk

CS is one of the most arrhythmogenic of the inflammatory cardiomyopathies. The patchy, heterogeneous fibrosis-fat replacement creates an ideal substrate for both reentrant ventricular tachycardia and disruption of the specialized conduction system. Sudden cardiac death (SCD) is a major cause of CS-related mortality.

Mechanism of Ventricular Tachycardia

The primary VT mechanism in CS is scar-mediated electrical reentry. As granulomas are replaced by fibrous and fatty tissue, the resulting scar creates zones of very slow conduction surrounded by normal or relatively normal myocardium. Electrical wavefronts entering these slow-conduction zones can reenter the adjacent myocardium after the refractory period has resolved — establishing a self-perpetuating reentrant circuit. This mechanism is analogous to post-infarction scar VT, but with important anatomical differences: CS scar is characteristically located at the basal septum, basal lateral wall, and subepicardial/mid-myocardial regions rather than in a specific coronary artery territory. VT circuits in CS are commonly epicardial or intramural, which has major implications for ablation approach.

Risk Factors for Sudden Cardiac Death in CS

Electrophysiology Study (EPS)

Programmed ventricular stimulation at EPS can assess inducibility of sustained VT. Inducibility of sustained monomorphic VT is a significant risk factor for future spontaneous VT/VF events and supports ICD implantation even when LVEF is relatively preserved (35–49%). EPS limitations in CS include: variable sensitivity depending on scar extent and location; inability to access epicardial circuits from endocardial stimulation; and false-negative studies in patients with predominantly mid-wall or epicardial substrate. Despite these limitations, EPS remains an important tool in CS risk stratification, particularly for the intermediate-risk group with LVEF 35–49% and no spontaneous sustained VT.

VT Ablation in Cardiac Sarcoidosis

Catheter ablation of VT is increasingly used in CS patients with recurrent VT storm or multiple ICD shocks despite optimal medical therapy and adequate corticosteroid treatment. CS ablation is technically among the most challenging of any VT substrate:

AV Block Management

High-grade AV block (Mobitz II or complete heart block) requires permanent pacing. The critical decision point is: which device to implant?

Back to Table of Contents

8. Treatment — Immunosuppression

Immunosuppressive therapy is the cornerstone of CS treatment. The goals are to: (1) suppress active granulomatous inflammation before irreversible fibrosis develops; (2) prevent progression of conduction system disease; (3) improve or stabilize LV systolic function; and (4) potentially reduce arrhythmia burden by treating active inflammation. There are no large randomized controlled trials of immunosuppression in CS (the rarity of the disease makes trial enrollment challenging), and treatment recommendations are based on observational data, registry studies, expert consensus, and extrapolation from systemic sarcoidosis trials.

Corticosteroids — First-Line Therapy

Starting dose: Prednisone 0.5–1.0 mg/kg/day (typically 40–60 mg/day for an average adult). Some experts initiate with pulse intravenous methylprednisolone (500–1000 mg/day × 3 days) for severe presentations with complete heart block, VT storm, or rapidly declining LVEF.

Response assessment: Serial FDG-PET at 3–6 months is the most sensitive measure of treatment response. LVEF on echocardiography, Holter monitoring (VT burden), and ECG (AV block) are important clinical response metrics. CMR LGE extent is less sensitive to short-term treatment response (established fibrosis does not reverse) but useful for long-term structural monitoring.

Taper schedule: Once disease activity is controlled (FDG-PET suppression, clinical stabilization), prednisone is tapered gradually over 6–12 months to a maintenance dose of 10–20 mg/day. Rapid tapering risks disease reactivation. Most CS experts recommend a minimum of 1–2 years of treatment; many patients require indefinite maintenance therapy.

Relapse on taper: Return of FDG-PET activity, decline in LVEF, recurrence of AV block, or increased VT burden during steroid taper signals relapse. Dose escalation plus addition of a steroid-sparing agent is the standard response.

Steroid-Sparing Immunosuppressive Agents

Used to reduce cumulative corticosteroid dose (limiting side effects), for incomplete response to steroids, or for patients requiring long-term immunosuppression:

Heart Failure Medical Therapy

CS patients with reduced LVEF should receive guideline-directed medical therapy (GDMT) for heart failure with reduced ejection fraction (HFrEF):

Note: Concurrent immunosuppression (particularly corticosteroids) can worsen diabetes mellitus, hypertension, and fluid retention — careful optimization of heart failure and metabolic therapy alongside immunosuppression is required. Monitoring serum electrolytes is particularly important given steroid-induced potassium wasting combined with MRA/ACE inhibitor use.

Back to Table of Contents

9. Device Therapy — ICD and CRT

Device therapy in CS addresses two problems: protection against sudden cardiac death from VT/VF, and optimization of cardiac mechanics in patients with conduction disease or LV dyssynchrony. Device decisions in CS are among the most nuanced in electrophysiology, requiring integration of arrhythmia risk, LV function, conduction system disease, and expected response to immunosuppression.

ICD Indications in Cardiac Sarcoidosis

Class I (strong recommendation — benefits clearly outweigh risks):

Class IIa (reasonable — benefits likely outweigh risks):

Class IIb (may be reasonable — uncertain benefit-risk balance):

Key principle: CS patients at any given LVEF have a higher rate of sudden cardiac death than age-matched patients with ischemic cardiomyopathy or idiopathic DCM at equivalent LVEF. This argues for a lower threshold for ICD implantation in CS, particularly for those with evidence of active disease or significant LGE. The ICD decision must also account for the possibility that LVEF may improve with corticosteroid therapy — but protection during the active inflammatory phase is critical.

Wearable Cardioverter-Defibrillator (WCD)

The WCD (LifeVest) may serve as an important bridge in newly diagnosed CS patients:

Cardiac Resynchronization Therapy (CRT)

Standard CRT indications apply to CS: LVEF ≤35% + LBBB morphology with QRS duration ≥150 ms (Class I), or LVEF ≤35% + non-LBBB wide QRS ≥150 ms or LBBB with QRS 120–149 ms (Class IIa). CRT may improve LV systolic function, reduce HF hospitalizations, and has survival benefit in these patients. In CS patients requiring pacing for AV block with reduced LVEF, CRT-D (CRT combined with ICD function) is preferred over single-site RV pacing. Excessive right ventricular apical pacing induces interventricular dyssynchrony that worsens LV function.

Physiological Pacing Strategies

His bundle pacing and left bundle branch area pacing (LBBAP) are emerging approaches that deliver physiological ventricular activation by capturing the native His-Purkinje conduction system distal to the site of block. In CS patients with AV block and preserved LVEF who require pacing, these approaches may be superior to RV apical pacing by preserving normal ventricular synchrony. LBBAP has become technically feasible with dedicated tools and is increasingly preferred at experienced centers. These techniques are particularly attractive in CS given the young age of most patients and the lifetime accumulation of dyssynchrony-related LV dysfunction from conventional RV apical pacing.

ICD Programming Considerations in CS

Back to Table of Contents

10. Monitoring and Long-term Follow-up

CS is a dynamic disease: granulomatous activity fluctuates, LVEF may improve or decline, and arrhythmia risk evolves over time. Structured longitudinal surveillance is essential to detect disease progression, treatment response, and complications early.

Scheduled Surveillance

Device Follow-up

ICD/CRT-D follow-up should include remote monitoring with daily device transmissions supplemented by in-person interrogation every 3–6 months. Device therapy (ATP, shocks) should be reviewed at every visit — ICD therapy for VT may be the first indication of disease progression or inadequate immunosuppression. Patients with multiple appropriate shocks or VT storm should be evaluated for treatment intensification, VT ablation referral, and reassessment of cardiac disease activity with FDG-PET.

Multidisciplinary Team

Optimal CS care requires coordinated input from: cardiologist (HF management), electrophysiologist (arrhythmia management, device therapy, ablation), pulmonologist (pulmonary sarcoidosis management), rheumatologist or sarcoidosis specialist (systemic immunosuppression), ophthalmologist (uveitis surveillance), endocrinologist (steroid-related diabetes), and transplant cardiology for advanced disease. Referral to a dedicated CS center of excellence is recommended for complex cases — particularly those with refractory VT, advanced heart failure, or diagnostic uncertainty.

Pregnancy in CS

CS in women of reproductive age requires specialized preconception counseling. Active disease or significantly reduced LVEF (<35%) significantly increases maternal and fetal risk. Corticosteroids are generally maintained during pregnancy with dose adjustment as clinically indicated. Methotrexate and mycophenolate are teratogenic and must be discontinued well before conception. Azathioprine has the most reassuring pregnancy safety data among steroid-sparing agents. ICD therapy is safe during pregnancy. Delivery planning should involve maternal-fetal medicine specialists and cardiology jointly.

Heart Transplantation Evaluation

End-stage CS unresponsive to immunosuppressive therapy, with refractory heart failure (LVEF <25%, NYHA III–IV despite GDMT), or refractory VT storm uncontrollable by ablation and ICD are indications for transplant evaluation. CS constitutes approximately 1–3% of cardiac transplant recipients at specialized centers. Outcomes after transplantation for CS are generally good, comparable to transplantation for other cardiomyopathies. Sarcoidosis can recur in the allograft, but clinically significant recurrence is uncommon. Careful post-transplant monitoring for cardiac allograft vasculopathy and sarcoid recurrence is required.

Back to Table of Contents

11. Prognosis

The prognosis of cardiac sarcoidosis is highly variable and has improved substantially with modern management — widespread use of implantable cardioverter-defibrillators, FDG-PET-guided immunosuppression, and multidisciplinary CS centers. However, CS remains a potentially lethal condition, and outcomes depend critically on the extent of cardiac involvement, timeliness of diagnosis, and response to treatment.

Overall Survival

Modern cohort studies from CS centers report 5-year survival of approximately 60–80% in clinically diagnosed CS. The Finnish nationwide registry (Kandolin et al., 2015) reported a 5-year survival of 78% in a well-characterized cohort with access to modern therapy. Historically, before systematic ICD use, CS-related SCD was a far more common cause of death. Most contemporary deaths are attributable to progressive heart failure rather than arrhythmic death — reflecting the success of ICD therapy in preventing SCD.

Predictors of Adverse Prognosis

LVEF Recovery with Immunosuppression

One of the most encouraging aspects of CS management is the potential for LVEF improvement with corticosteroid therapy. Among patients with active inflammation (FDG-PET positive, early disease), LVEF improvement of ≥10 percentage points is reported in 40–70% of patients treated with adequate corticosteroid regimens. Patients who achieve FDG-PET suppression (complete metabolic response) and LVEF normalization have the best long-term prognosis and may be candidates for consideration of ICD deactivation (with strict ongoing follow-up) if they have remained free of VT for an extended period.

Right Heart and Pulmonary Outcomes

Patients with significant pulmonary hypertension or cor pulmonale from CS have substantially worse prognosis. RV failure is a major driver of late mortality in CS patients who survive the initial arrhythmia risk period. Appropriate management of pulmonary hypertension (including pulmonary vasodilators when indicated for WHO Group 1 pulmonary vascular sarcoidosis) and RV support is an important component of comprehensive CS care.

Cardiac Transplantation Outcomes

CS patients who undergo cardiac transplantation have survival outcomes comparable to other cardiomyopathy diagnoses at experienced centers. Sarcoidosis recurrence in the cardiac allograft occurs in a minority of recipients (estimated 10–15% in careful histological follow-up studies), but clinically significant recurrent CS causing graft dysfunction is uncommon when monitored appropriately. Post-transplant immunosuppression regimens overlap substantially with sarcoidosis therapy, which may partially suppress allograft granuloma formation. Long-term graft survival in CS transplant recipients is not significantly different from other non-inflammatory cardiomyopathy etiologies.

Back to Table of Contents

12. Research Papers

  1. Birnie DH et al. HRS Expert Consensus Statement on the Diagnosis and Management of Arrhythmias Associated With Cardiac Sarcoidosis. Heart Rhythm. 2014;11(7):1305-1323.
  2. Kandolin R et al. Cardiac sarcoidosis: epidemiology, characteristics, and outcome over 25 years in a nationwide study. Circulation. 2015;131(7):624-632.
  3. Sekhri V et al. Cardiac sarcoidosis: a comprehensive review. Arch Med Sci. 2011;7(4):546-554.
  4. Ekstrom K et al. Cardiac involvement in sarcoidosis: evolution and prognosis. Heart. 2016;102(18):1443-1448.
  5. Nery PB et al. Prevalence of cardiac sarcoidosis in patients presenting with monomorphic ventricular tachycardia. Pacing Clin Electrophysiol. 2014;37(3):364-374.
  6. Schuller JL et al. Electroanatomic mapping and catheter ablation of ventricular tachycardia in cardiac sarcoidosis. Heart Rhythm. 2012;9(10):1562-1570.
  7. Patel MR et al. Low diagnostic yield of elective coronary angiography. N Engl J Med. 2010;362(10):886-895.
  8. Terasaki F et al. Guidelines for diagnosis of cardiac sarcoidosis. Study Group of Sarcoidosis. Jpn Circ J. 1993;57(9):829-832.
  9. Blankstein R et al. Myocardial perfusion imaging and FDG PET in cardiac sarcoidosis. JACC Cardiovasc Imaging. 2014;7(5):481-490.
  10. Mehta D et al. Cardiac involvement in patients with sarcoidosis. Chest. 2008;133(6):1426-1435.
  11. Isobe M et al. Cardiac sarcoidosis. Ann Vasc Dis. 2016;9(4):241-254.
  12. Segawa M et al. Clinicopathological characteristics of cardiac sarcoidosis causing sudden death, including 11 autopsy cases. Circ Arrhythm Electrophysiol. 2016;9(5):e003579.

Back to Table of Contents

Connections

Back to Table of Contents