Prognostic role of NYHA class in heart failure patients undergoing primary prevention ICD therapy

Abstract

Abstract Aims Concerns about the prognostic value of NYHA functional class (FC) in heart failure (HF) patients carrying a prophylactic implantable cardioverter defibrillator (ICD) are still present. We aimed to compare whether mortality and arrhythmic risk were different, in a cohort of HF patients undergoing ICD‐only implant, according to their FC. Methods and results HF patients with left ventricle ejection fraction (LVEF) ≤35%, undergoing first prophylactic ICD‐only implant were collected from a multicentre nationwide registry (2006–2015). Six hundred and twenty‐one patients were identified (101 patients in NYHA I; 411 in NYHA II; 109 in NYHA III). After a mean follow‐up of 4.4 years (±2.1), 126 patients died (20.3%). All‐cause mortality risk was higher in symptomatic patients: 13.9% in NYHA I patients, 18.3% in NYHA II patients (HR: 1.8, 95% CI 1.1–3.2), and 32.9% in NYHA III patients (HR: 3.9, 95% CI 2.1–7.3). Seventy‐eight out of all deaths were due to cardiovascular causes (12.6%). Cardiovascular mortality risk was also higher in symptomatic patients: 6.9% in NYHA I patients, 11% in NYHA II patients (HR: 2.2, 95% CI 1.1–4.9), and 23.9% in NYHA III (HR: 5.5, 95% CI 2.4–12.7). One hundred and seventeen patients received a first appropriate ICD therapy (19.4%). Arrhythmia free survival did not differ among study groups [20.8% in NYHA I patients, 18.7% in NYHA II (HR: 1.1, 95% CI 0.6–1.7) and 20.8% in NYHA III patients (HR: 1.3, 95% CI 0.7–2.5)]. NYHA class independently predicted cardiovascular mortality (NYHA III vs. NYHA I: HR, 4.7; 95% CI, 1.7–12.8, P = 0.002; NYHA II vs. NYHA I: HR, 2.1, 95% CI, 1.0–5.6, P = 0.05) but not all‐cause death (NYHA III vs. NYHA I: HR: 1.8, 95% CI 0.8–3.9, P = 0.11; NYHA II vs. NYHA I: HR, 1.1, 95% CI 0.6–2.2, P = 0.71;). Atrial fibrillation, chronic kidney disease, and diabetes emerged as predictors of both all‐cause death [(HR: 1.8, 95% CI 1.2–2.8, P = 0.005), (HR: 2.2, 95% CI 1.4–3.4, P < 0.001), (HR: 2.0, 95% CI 1.3–3.1, P = 0.001), respectively] and cardiovascular mortality [(HR: 1.8, 95% CI 1.1–3.1, P = 0.02), (HR: 3.1, 95% CI 1.8–5.4, P < 0.001), (HR: 1.7, 95% CI 1.1–3, P = 0.032), respectively]. Conclusions Mortality in HF patients undergoing prophylactic ICD implantation was higher in symptomatic patients. NYHA functional class along with other comorbidities might be helpful to identify a subgroup of ICD carriers with poorer prognosis and higher risk of cardiovascular death.

Keywords

• Prognosis
• NYHA functional class
• Implantable cardioverter defibrillator