Chronic cardiac resynchronization therapy reverses cardiac remodelling and improves invasive haemodynamics of patients with severe heart failure on optimal medical treatment

Aims The aim of this study was to assess chronic invasive haemodynamic effects of cardiac resynchronization therapy (CRT) in patients with severe heart failure. Methods and results Seventeen patients with New York Heart Association (NYHA) class III or IV and QRS duration > 120 ms on optimal treatments underwent CRT. Haemodynamic data were obtained by cardiac catheterization before and 1 month after CRT. Clinical parameters and exercise tolerance were also evaluated. Chronic CRT improved haemodynamics significantly; mean pulmonary capillary wedge pressure decreased from 15.9 (+/-) 6.1 to 10.2 +/- 5.3 mmHg (P < 0.05), systolic pulmonary artery pressure decreased from 36.5 +/- 13.2 to 26.7 +/- 11.9 mmHg (P < 0.05), left ventricular end-diastolic pressure decreased from 15.6 +/- 7.2 to 10.5 +/- 7.3 mmHg (P < 0.05), end-diastolic volume decreased from 358.8 +/- 84.6 to 322.9 +/- 99.0 mL (P < 0.05), end-systolic volume decreased from 264.1 +/- 67.6 to 219.2 +/- 74.3 mL (P < 0.05), left ventricular ejection fraction increased from 25.4 +/- 6.2 to 33.1 +/- 4.9% (P < 0.05), and cardiac index increased from 1.9 +/- 0.4 to 2.2 +/- 0.5 L/min/m(2) (P < 0.05). Chronic CRT significantly improved functional capacity such as NYHA classification, 6 min walk distance, and peak oxygen uptake. Conclusion Chronic CRT improved not only symptoms and exercise tolerance but also invasive haemodynamics associated with reversed cardiac remodelling.