title: Impact of mitral regurgitation and myocardial viability on left ventricular reverse remodeling after cardiac resynchronization therapy in patients with ischemic cardiomyopathy.
abstract: This study investigated the impact of ischemic mitral regurgitation (MR) severity and viability on left ventricular (LV) reverse remodeling after cardiac resynchronization therapy (CRT) in patients with ischemic cardiomyopathy. Severe MR and ischemic cardiomyopathy have been associated with lack of LV reverse remodeling after CRT. Fifty-seven consecutive patients with ischemic MR, LV ejection fraction < or =35%, QRS duration > or =120 ms, and intraventricular dyssynchrony > or =50 ms were prospectively included. Stress echocardiography was performed before CRT implantation. Viability in the region of the LV pacing lead was defined as the presence of viability in 2 contiguous segments. Response to CRT at 6 months was defined by evidence of > or =15% LV decrease in end-systolic volume. Severe MR was defined by an effective regurgitant orifice (ERO) area > or =20 mm(2). Thirty-three patients (58%) were responders at follow-up. Baseline ERO area and prevalence of severe MR were not different between responders and nonresponders (19 +/- 11 vs 21 +/- 13 mm(2), p = 0.67; 52% vs 53%, p = 0.84). In responders, MR was decreased by 58% (ERO 19 +/- 12 to 8 +/- 6 mm(2)). In the presence of viability in the region of the pacing lead, 74% (n = 29 patients) were responders (sensitivity 88%, specificity 58%); in the subgroup of patients with viability in the region of the pacing lead and severe MR, 83% (n = 17 patients) were responders. In conclusion, LV remodeling is frequent and ischemic MR decrease important in patients with viability in the region of the pacing lead without regard to MR severity.
authors.affiliation: Department of Cardiology, Institut Universitaire de Cardiologie et de Pneumologie de Québec, Quebec, PQ, Canada. mario.senechal@criucpq.ulaval.ca
authors.forename: Mario
authors.initials: M
authors.lastname: Sénéchal
authors.forename: Patrizio
authors.initials: P
authors.lastname: Lancellotti
authors.forename: Julien
authors.initials: J
authors.lastname: Magne
authors.forename: Patrick
authors.initials: P
authors.lastname: Garceau
authors.forename: Jean
authors.initials: J
authors.lastname: Champagne
authors.forename: François
authors.initials: F
authors.lastname: Philippon
authors.forename: Gilles
authors.initials: G
authors.lastname: O'Hara
authors.forename: Marie
authors.initials: M
authors.lastname: Moonen
authors.forename: Michelle
authors.initials: M
authors.lastname: Dubois
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial; D009202:Cardiomyopathies / Q000150:complications* / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000150:complications*; D010138:Pacemaker, Artificial; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D020257:Ventricular Remodeling