CRT15: UNSTABLE HEART FAILURE AS A TARGET FOR CARDIAC RESYNCHRONISATION THERAPY

Background The symptomatic benefits of cardiac resynchronisation therapy(CRT) in stable heart failure are well established. No studies have explored the role of CRT in patients with unstable heart failure. Methods 28 patients [age 65.2 (2.4) yrs [mean (SEM)] who had an acute exa cerbation of heart failure within a month (n=20) or within 1 week (n=8) of pacemaker implantation underwent a 6-min walk test, quality of life assessment (Minnesota Living with Heart Failure questionnaire) and echocardiography before and after CRT. Results Over 458 (66) days of follow-up, NYHA class improved from 3.5 (0.1) at baseline, to 1.9 (0.2) at 1 month (F1) and 2.2 (0.2) at the latest follow-up visit (F2) (both p<0.0001). Walking distance increased from 215.9 (20.9) to 291.5 (25.9) at F1 (p<0.01) and 340.9 (17.2) m at F2 (p=0.0002). Quality of life scores improved from 66.5 (3.7) to 42.5 at F1 (p=0.0013) and 39.7 (5.2) at F2 (p<0.0001). There was, in addition, a reduction in left ventricular end-diastolic [223.7 (15.9) to 216.7 (19.3) at F1 (p=0.06) and 192.1 (22.8) at F2 (p=0.01)] and end-systolic [(163.6 (16.2) to 154.8 (19.2) at F1 (p=0.0175) and 135.8 (20.8) ml at F2 (p=0.025)] volumes. Left ventricular ejection fraction increased from 0.29 (0.02) to 0.32 (0.03) at F1 (p=NS) and 0.34 (0.03) at F2 (p=0.0146). No significant change in QRS duration was observed [157.7 (5.9) ms at baseline]. Conclusion CRT leads to sustained, long-term symptomatic improvement and reverse left ventricular remodelling in patients with a recent acute exacerbation of heart failure. These findings call for randomised studies of CRT in patients with unstable heart failure.