Outcomes of definite vs probable/presumed cardiac sarcoidosis: a systematic review and meta-analysis

Background: Diagnosing cardiac sarcoidosis (CS), which can be associated with arrhythmias and heart failure, remains challenging despite multiple advances over time. The 2014 Heart Rhythm Society (HRS) consensus statement recommends an endomyocardial biopsy (EMB) to establish a definite diagnosis of CS. In the absence of a positive EMB, a diagnosis of probable or presumed CS is made on the basis of clinical and imaging criteria.

Objective: To investigate whether there is any difference in outcomes between definite vs probable/presumed CS.

Methods: PubMed/MEDLINE, Embase, and the Cochrane Library databases were searched for relevant studies published after 2014. Risk ratios (RR) with 95% confidence intervals (CI) were calculated using the random effects model and presented in forest plots.

Results: 6 studies involving 2,204 patients were identified. The cohort had a mean age of 56.8 years (SD: ±13.6 years). The median duration of follow-up was 40.5 months. No statistically significant difference was observed between definite and probable/presumed CS for reduced risk of the composite endpoint (RR: 1.80, 95% CI: 0.93 to 3.49), and all-cause death (RR: 1.01, 95% CI: 0.48 to 2.10).

Conclusion: This meta-analysis demonstrated the equivalence of clinical course and prognosis between definite and probable/presumed CS. This highlights the importance of a multi-disciplinary approach to CS care and emphasizes that histological confirmation should not be a prerequisite to diagnose or manage this condition.