Background—: This study was designed to assess the epidemiology, characteristics, and outcome of cardiac sarcoidosis (CS) in Finland. Methods and Results—: We identified in retrospect all adult (>18 years of age) patients diagnosed with histologically confirmed CS in Finland between 1988 and 2012. A total of 110 patients (71 women) 51±9 years of age (mean±SD) were found and followed up for outcome events to the end of 2013. The annual detection rate of CS increased >20-fold during the 25-year period, reaching 0.31 in 1×10 ⁵ adults between 2008 and 2012. The 2012 prevalence of CS was 2.2 in 1×10 ⁵ . Nearly two thirds of patients had clinically isolated CS. Altogether, 102 of the 110 patients received immunosuppressive therapy, and 56 received an intracardiac defibrillator. Left ventricular function was impaired (ejection fraction <50%) in 65 patients (59%) at diagnosis and showed no overall change over 12 months of steroid therapy. During follow-up (median, 6.6 years), 10 patients died of a cardiac cause, 11 patients underwent transplantation, and another 11 patients suffered an aborted sudden cardiac death. The Kaplan–Meier estimates for 1-, 5-, and 10-year transplantation-free cardiac survival were 97%, 90%, and 83%, respectively. Heart failure at presentation predicted poor outcome (log-rank P =0.0001) with a 10-year transplantation-free cardiac survival of only 53%. Conclusions—: The detection rate of CS has increased markedly in Finland over the last 25 years. With current therapy, the prognosis of CS appears better than generally considered, but patients presenting with heart failure still have poor long-term outcome.

Cardiac sarcoidosis (CS) results from epithelioid cell granulomas infiltrating the myocardium and predisposing to conduction disturbances, ventricular tachyarrhythmias, and heart failure. Manifest CS, however, constitutes only the top of an iceberg as advanced imaging uncovers cardiac involvement 4 to 5 times more commonly than what is clinically detectable. Definite diagnosis of CS requires myocardial biopsy and histopathology, but a sufficient diagnostic likelihood can be achieved by combining extracardiac histology of sarcoidosis with clinical manifestations and findings on cardiac imaging. CS can appear as the first or only organ manifestation of sarcoidosis or on top of pre-existing extracardiac disease. Due to the lack of controlled trials, the care of CS is based on observational evidence of low quality. Currently, the treatment involves corticosteroid-based, tiered immunosuppression to control myocardial inflammation with medical and device-based therapy for symptomatic atrioventricular block, ventricular tachyarrhythmias, and heart failure. Recent outcome data indicate 90% to 96% 5-year survival in manifest CS with the 10-year figures ranging from 80% to 90%. Major progress in the care of CS awaits the key to its molecular–genetic pathogenesis and large-scale controlled clinical trials.

Aims In aortic stenosis (AS), left ventricular (LV) hypertrophy is considered a compensatory response helping maintain systolic function. Recent research in experimental AS suggests, however, that LV hypertrophy is not necessary to sustain LV contractions but may in fact be maladaptive. The present work aimed to clarify the role of LV hypertrophy in AS-related heart failure (HF) in man. Methods and results We studied 137 adult patients with isolated AS undergoing pre-operative echocardiography and cardiac catheterization. HF was diagnosed by the European criteria and LV hypertrophy by sex-specific limits of echocardiographic LV mass. The higher the LV mass was, the poorer was the LV ejection fraction (β=−0.26, P<0.001, linear regression) and the greater the likelihood of HF independent of the severity of AS (P<0.001, logistic regression). In the subgroup of critical AS (valve area <0.4 cm²/m², n=85), patients with absent LV hypertrophy (n=19) had better preserved ejection fraction (mean±SE, 64±3 vs. 57±2%, P=0.045) and less HF (16 vs. 48%, P=0.025) than patients with LV hypertrophy (n=66). Conclusion In isolated AS, increased LV mass predicts the presence of systolic dysfunction and HF independent of the severity of valvular obstruction. LV hypertrophy may be maladaptive rather than beneficial in AS in man.

Background: Cardiac sarcoidosis (CS) predisposes to sudden cardiac death (SCD). Guidelines for implantable cardioverter defibrillators (ICDs) in CS have been issued by the Heart Rhythm Society in 2014 and the American College of Cardiology/American Heart Association/Heart Rhythm Society consortium in 2017. How well they discriminate high from low risk remains unknown. Methods: We analyzed the data of 398 patients with CS detected in Finland from 1988 through 2017. All had clinical cardiac manifestations. Histological diagnosis was myocardial in 193 patients (definite CS) and extracardiac in 205 (probable CS). Patients with and without Class I or IIa ICD indications at presentation were identified, and subsequent occurrences of SCD (fatal or aborted) and sustained ventricular tachycardia were recorded, as were ICD indications emerging first on follow-up. Results: Over a median of 4.8 years, 41 patients (10.3%) had fatal (n=8) or aborted (n=33) SCD, and 98 (24.6%) experienced SCD or sustained ventricular tachycardia as the first event. By the Heart Rhythm Society guideline, Class I or IIa ICD indications were present in 339 patients (85%) and absent in 59 (15%), of whom 264 (78%) and 30 (51%), respectively, received an ICD. Cumulative 5-year incidence of SCD was 10.7% (95% CI, 7.4%–15.4%) in patients with ICD indications versus 4.8% (95% CI, 1.2%–19.1%) in those without (χ ² =1.834, P =0.176). The corresponding rates of SCD were 13.8% (95% CI, 9.1%–21.0%) versus 6.3% (95% CI, 0.7%–54.0%; χ ² =0.814, P =0.367) in definite CS and 7.6% (95% CI, 3.8%–15.1%) versus 3.3% (95% CI, 0.5%–22.9%; χ ² =0.680, P =0.410) in probable CS. In multivariable regression analysis, SCD was predicted by definite histological diagnosis ( P =0.033) but not by Class I or IIa ICD indications ( P =0.210). In patients without ICD indications at presentation, 5-year incidence of SCD, sustained ventricular tachycardia, and emerging Class I or IIa indications was 53% (95% CI, 40%–71%). By the American College of Cardiology/American Heart Association/Heart Rhythm Society guideline, all patients with complete data (n=245) had Class I or IIa indications for ICD implantation. Conclusions: Current ICD guidelines fail to distinguish a truly low-risk group of patients with clinically manifest CS, the 5-year risk of SCD approaching 5% despite absent ICD indications. Further research is needed on prognostic factors, including the role of diagnostic histology. Meanwhile, all patients with CS presenting with clinical cardiac manifestations should be considered for an ICD implantation.

In cardiac sarcoidosis (CS), the risk and predictors of new-onset atrial fibrillation (AF) are poorly known. The authors evaluated the incidence and characteristics of AF in newly diagnosed CS. The authors studied 118 patients (78 women, mean age 50 years) with AF-naive CS having undergone cardiac ¹⁸F-fluorodexoyglucose positron emission tomography (¹⁸F-FDG PET) at the time of diagnosis. Details of patient characteristics and medical or device therapy were collected from hospital charts. The PET scans were re-analyzed for presence of atrial and ventricular inflammation, and coincident cardiac magnetic resonance (CMR) studies and single-photon emission computed tomography (SPECT) perfusions were analyzed for cardiac structure and function, including the presence and extent of myocardial scarring. Detection of AF was based on interrogation of intracardiac devices and on ambulatory or 12-lead electrocardiograms. Altogether 34 patients (29%) suffered paroxysms of AF during follow-up (median, 3 years) with persistent AF developing in 7 patients and permanent AF in 4. The estimated 5-year incidence of AF was 55% (95% CI: 34%-72%) in the 39 patients with atrial ¹⁸F-FDG uptake at the time of diagnosis vs 18% (95% CI: 10%-28%) in the 79 patients without atrial uptake (P < 0.001). In cause-specific Cox regression analysis, atrial uptake was an independent predictor of AF (P < 0.001) with HR of 6.01 (95% CI: 2.64-13.66). Other independent predictors were an increased left atrial maximum volume (P < 0.01) and history of sleep apnea (P < 0.01). Ventricular involvement by PET, SPECT, or CMR was nonpredictive. Symptoms of AF prompted electrical cardioversion in 12 patients (35%). Three of the 34 patients (9%) experiencing AF suffered a stroke versus none of those remaining free of AF. In newly diagnosed CS, future AF is relatively common and associated with atrial inflammation and enlargement on multimodality cardiac imaging.