Undetected Heart Failure in Cardiology: Prevalence, Characteristics, and Outcome

To confirm or refute recent pilot studies showing unexpectedly high rates of undetected heart failure (HF) in cardiology patients.

We assessed the prevalence, characteristics, and outcome of undetected HF in a large prospective cohort study of patients referred for non-invasive coronary artery disease (CAD) work-up with cardiac positron emission tomography computed tomography. HF presence and phenotype were centrally adjudicated by an independent cardiologist according to clinical practice guidelines requiring three mandatory criteria: symptoms, elevated natriuretic peptides, and structural/functional cardiac abnormalities. The endpoint was a composite of cardiovascular death and acute HF (AHF) hospitalization through 2-year of follow-up.

Among 1738 eligible patients (median age 67 years, 30% women), 138 patients (7.9%) had known HF, and 534 of 1600 patients (33.4%) without known HF had adjudicated undetected HF, resulting in a ratio of undetected HF to known HF of 3.9 (95%CI, 3.2-4.7)-to-1 and a number needed to screen to detect one patient with undetected HF of 3.0 (95%CI, 2.9-3.1). In undetected HF, left ventricular ejection fraction (LVEF) was preserved in 72.3%, mildly reduced in 16%, and reduced in 11.7%. Older age, known CAD, atrial fibrillation, previous pacemaker implantation, and ECG abnormalities were associated with a higher likelihood for undetected HF. Undetected HF was associated with an increased cumulative incidence of the composite endpoint (adjusted subdistribution hazard ratio 7.37 [95%CI, 3.87-14.06], p<0.001, versus no HF).

One-out-of three patients referred for CAD work-up had undetected HF, which was associated with cardiovascular death and AHF hospitalization.