Awareness of indications for device therapy among a broad range of physicians: a survey study

Cardiac resynchronization therapy (CRT) and primary prophylactic implantable cardioverter-defibrillators (ICDs) are underutilized in heart failure (HF). This may originate from an unawareness of device benefits and indications among physicians responsible for HF care and referral. We aimed to describe the awareness of indications for device therapy in a generalized sample of Swedish physicians.

A randomly selected sample of Swedish physicians specializing in cardiology, internal medicine, and family medicine and interns (5% of eligible physicians, n = 519) was invited to fill in a 23-item survey, testing their awareness of indications for device therapy and, as comparison, pharmacological therapy. Acceptable awareness (AA) of CRT indication was predefined as recognizing that a left bundle branch block on ECG warrants further evaluation for CRT. Acceptable awareness of ICD indication was predefined as recognizing that ejection fraction ≤35% alone, without a history of ventricular tachycardia, is sufficient to warrant a primary prophylactic ICD. The response rate was 37% (n = 168). Overall, 32% met AA of CRT indication, and significantly less (15%) met AA of ICD indication. Specialist certification in cardiology was the only significant predictor for AA [odds ratio (95% confidence interval): 37 (10-138)]. However, even among cardiologists, awareness of ICD indications was low (61% with AA). Guideline-recommended indications for pharmacological therapy were conceived significantly better (P = 0.02) than device therapy [median (interquartile range) of correct answers: 50% (33-50) compared with 36% (14-57)].

The study identified an important and substantial awareness gap in the medical community that may explain some of the previously reported low referral rates and utilization of device therapy in HF.