Influence Of Diastolic Filling Pattern On Cardiac Resynchronization Therapy In Patients With Nonischemic Cardiomyopathy

Objective Diastolic function is an important component of overall cardiac function. This study aimed to explore the influence of diastolic filling pattern on cardiac res ynchronization therapy (CRT) in patients with nonischemic cardiomyopathy.Methods Between January 2012 and September 2013,100 patients with nonischemic cardiomyopathy undergoing CRT were enrolled in the study, all patients were grouped by the pre-CRT diastolic filling pattern as impaired relaxation, pseudonormalized and restrictive filling. Followed up for 12 months, the New York Heart Association (NYHA) Class and echocardiography were used to assess the efficacy of CRT; the endpoint included re-hospitalization for heart failure or cardiac death. Kaplan-Meier survival curve was used to assess the prognosis.Results All patients had varying degrees of diastolic dysfunction.Logistic regression analysis indicated that diastolic filling pattern was the independent factor for the respond of CRT. (1)The response rate (78.7%) of impaired relaxation group (n= 61) was significantly higher than that of any other groups (P<0.01):postoperative NYHA class, LVEF, FS, LVESV and LVEDV were significantly improved (all P<0.01). (2)For pseudonormalized group(n=18),at 3 months, NYHA class decreased from 3.3±0.5 to 2.3±0.5,LVEF increased from 27.2±6.7% to 30.6±6.1%(both P<0.01) and FS improved significantly (P<0.05); no significant decrease of LVEDV and LVESV. At 6 months, LVEF improved significantly (P <0.01); LVESV was reduced (P<0.05). (3)In restrictive filling group (n=21), CRT brought short-term improvement in NYHA class but did not induce any significant improvement in LVEF, FS, LVESV and LVEDV. At 6 months, there were significant differences in efficacy among the three groups (P<0.05). At the end of follow-up,5 patients died, the cumulative endpoint incidence was significantly higher in restrictive filling group (81%) than other groups (P<0.05).Conclusion In patients with moderate-to-severe heart failure,left ventricular diastolic dysfunction affects the efficacy of CRT, patients with impaired relaxation benefit significantly, pseudonormalized take longer to benefit, but patients with restrictive filling do not benefit from CRT.