The Effects of Cardiac Resynchronization Therapy on Cardiovascular and Non-cardiovascular Hospitalization: A Long-term Follow-up MADIT-CRT Sub-study

Little is known about the effects of cardiac resynchronization therapy (CRT-D) on hospitalizations during long-term follow up. We assessed the impact of CRT-D on CV and non-CV hospitalizations in patients randomized to implantable cardioverter-defibrillator (ICD) or CRT-D in the MADIT-CRT trial.

MADIT-CRT randomized 1820 patients with mild heart failure (HF), low ejection fraction and a wide QRS to ICD or CRT-D. Hospitalization rates and lengths of hospital stay were compared. At an average of 5.6 years follow-up, there was a lower rate of all-cause hospitalizations in the CRT-D arm compared with the ICD group (72.6 events per 100 pt-years versus 82.6 events per 100 pt-years, p=0.020). This was driven by a reduction in CV-hospitalizations with CRT-D vs. ICD (28.8 events per 100 pt-years vs. 42.6 events per 100 pt-years, p<0.001), and a reduction in HF hospitalizations (11.9 events per 100 pt-years vs. 22.4 events per 100 pt-years, p<0.001). There was no significant difference in non-CV hospitalizations in the CRT-D group compared to ICD (43.8 vs. 39.9 events per 100 pt-years, p=0.166). The length of hospital stay for any cause was similar with CRT-D (14.8±1.06 days) compared with the ICD group (14.7±0.95 days; p=0.06). The length of stay for cardiovascular hospitalizations was shorter for the CRT-D group (6.7±0.89 days) compared with the ICD group (7.7±0.68 days); p<0.001. The length of stay for heart failure related hospitalizations was shorter for the CRT-D group (4.2±0.79 days) compared with the ICD group (4.8±0.58 days); p<0.001. The length of stay for non-cardiovascular hospitalizations was not significantly different (8.1 vs. 7 days, p=0.08). Any hospital admission was associated with an increased risk of death (HR 8.97 95%CI 6.17-13.05).

Among patients with NYHA class I/II heart failure, CRT-D therapy significantly reduces all-cause hospitalizations, HF, and CV hospitalizations with reductions in hospital length of stay. Any hospitalization was associated with an increased risk of death.