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.