Gender-related safety and efficacy of cardiac resynchronization therapy

Abstract

Background: Cardiac resynchronization therapy (CRT) is an established therapy for patients with chronic heart failure (CHF) and a broad QRS complex. Gender-related safety and efficacy data are necessary for informed patient decision-making for female patients with CHF. The aim of the study was to assess the effects of gender on the outcome of CRT in highly symptomatic heart failure patients.

Hypothesis: Gender may have an effect on the outcome of heart failure patients undergoing cardiac resynchronisation therapy.

Methods: The study analyzed the 2-year follow-up of 393 New York Heart Association (NYHA) class III/IV patients with a class I CRT indication enrolled in the Management of Atrial Fibrillation Suppression in AF-HF Comorbidity Therapy (MASCOT) study.

Results: In female patients (n = 82), compared with male patients (n = 311), CHF was more often due to dilated cardiomyopathy (74% vs 44%, respectively; P < 0.0001). Females also had a more impaired quality-of-life score and a smaller left ventricular end-diastolic diameter (LVEDD). Women were less likely than men to have received a CRT defibrillator (35% vs 61%, respectively; P < 0.0001). After 2 years, the devices had delivered more biventricular pacing in women than in men (96% ± 13% vs 94% ± 13%, respectively; P < 0.0004). Women had a greater reduction in LVEDD than did men (-8.2 mm ± 11.1 mm vs -1.1 mm ± 22.1 mm, respectively; P < 0.02). Both genders improved similarly in NYHA functional class. Women reported greater improvement than men in quality-of-life score (-21.1 ± 26.5 vs -16.2 ± 22.1, respectively; P < 0.0001). After adjustment for cardiovascular history, women had lower all-cause mortality (P = 0.0007), less cardiac death (P = 0.04), and fewer hospitalizations for worsening heart failure (P = 0.01).

Conclusions: Females exhibited a better response to CRT than did males. Because females have such impressive benefits from CRT, improved screening and advocacy for CRT implantation in women should be considered.

Figure 1

At baseline, women had a significantly smaller LV end‐diastolic diameter than did men (P = 0.0009); after 2‐year follow‐up, women had a significantly greater reduction of LV end‐diastolic diameter than did men (P < 0.02). Abbreviations: LV, left ventricular.

Figure 2

(A) After 2‐year follow‐up, women had lower all‐cause mortality (P = 0.008), lower cardiac mortality (P = 0.04), and fewer hospitalizations due to worsening heart failure (P = 0.045) than did men. (B) The Kaplan‐Meier curve for time to death shows a significantly better survival for women than for men (P = 0.006).