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Background: We sought to investigate the effect of cardiac resynchronization therapy (CRT) on disease progression in patients with moderate left ventricular (LV) systolic dysfunction. Methods and Results: This is a prospective study to explore the effect of CRT in 15 optimally treated patients (age: 66.1 ± 12.8 years; male = 13) with New York Heart Association (NYHA) class III, LV ejection fraction >35% and <45% and QRS duration >120 msec. Echocardiographic examination and standard heart failure assessment was performed before and 3 months after CRT implantation. The magnitude of echocardiographic remodeling measurements was compared with 30 age, sex, NYHA class, and heart failure etiology matched patients with conventional CRT indication. There were significant reductions in LV end-systolic (86.2 ± 24.1 to 69.7 ± 22.2 mL, P < 0.01)/end-diastolic (135.5 ± 36.8 to 120.5 ± 34.6 mL, P < 0.01) volumes, improvement in LV ejection fraction (39.1 ± 2.2 to 44.2 ± 5.5%, P = 0.01), and NYHA class (3.0 ± 0.0 to 2.07 ± 0.46, P < 0.001). There was no difference in changes in LV volumes, ejection fraction, NYHA class, and exercise capacity before and after CRT between the study and conventional groups except for greater improvement in the quality of life score in the conventional group. Conclusion: In this prospective study, significant LV reverse remodeling by CRT in those with a wide QRS complex and moderate LV systolic dysfunction was observed. Further studies to explore the benefit of CRT in patients with less severe heart failure are recommended. [ABSTRACT FROM AUTHOR]

Abstract: Background: Carvedilol exerted a greater reduction in mortality than metoprolol tartrate in the Carvedilol or Metoprolol European Trial (COMET). However, it is unclear if the degree and time course of β1-blockade during a 24-h period was similar with each agent at the doses used. Therefore we analyzed 24-h ECG Holter recordings from a study which compared the long-term clinical efficacy of metoprolol tartrate to carvedilol in chronic heart failure patients using the same dosing regimen as in COMET. Methods and results: Fifty-one patients with chronic heart failure with a mean LVEF 26±1.8% were randomized in a double-blind fashion to receive metoprolol tartrate 50 mg bid or carvedilol 25 mg bid. 24-h ECG monitoring (Holter) was performed at baseline, 12 weeks and 1 year. Adequate quality recordings for analysis were obtained from 43 subjects at baseline, 42 at 12 weeks and 29 subjects at 1 year. Both drugs produced a fall in average 24-h heart rate from baseline at 12 weeks and at 1 year: metoprolol 88±3 to 71±2 and 69±3 bpm; carvedilol 83±3 to 70±2 and 70±3 bpm respectively (all p &#60;0.001). The pattern of suppression of heart rate during the 24-h period was similar for both drugs. Conclusion: Metoprolol tartrate 50 mg bid and carvedilol 25 mg bid had similar effects on 24-h heart rate. This result suggests that the degree of β1-blockade produced by these two drugs in these doses is comparable and the superior survival effect of carvedilol compared to metoprolol seen in COMET is likely to be due to actions of carvedilol other than β1-blockade. [Copyright &y& Elsevier]

Abstract: Background: Proven medical therapy is under-prescribed in heart failure (HF) for various reasons. Cardiac resynchronization therapy (CRT) is of proven value in selected patients with HF; however, the degree of benefit in those without the optimal therapy is not clear. Methods: This is a retrospective study comparing the effect of CRT in 30 patients without optimal combination therapy (group 1; 10 (33%) without ACEi or equivalent and 25 (83%) without beta-blockers) to an age, sex, ejection fraction (EF) and New York Heart Association (NYHA) class matched control but with the combination (group 2; n =30) at baseline. All patients were in NYHA class III or IV with EF ≤35% and QRS interval≥120 ms. Echocardiographic examination and N-terminal pro-brain natriuretic peptide (NT pro-BNP) levels before and 3 months after CRT were compared between the two groups. The composite endpoints of HF hospitalization or death during follow-up were compared by Kaplan–Meier analysis. Results: There were significantly less improvement in EF (+4.0±2.5% vs +10.1±3.2%; p <0.05) and degree of reverse remodeling in group 1 after 3 months. Patients in group 1 had significantly higher level of NT pro-BNP levels at 3 months (2221±2001 pg/mL vs 1038±905 pg/mL; p <0.001) and higher rates of HF hospitalization or death (53.3% vs 23.3%; Log rank χ 2 5.52; p =0.019). Conclusion: Patients receiving CRT but without optimal medical therapy were associated with less echocardiographic and clinical improvement. Optimal medical therapy, if tolerated, before CRT is necessary. [Copyright &y& Elsevier]

Objectives: This study was designed to evaluate the role of cardiac resynchronization therapy (CRT) in heart failure (HF) patients with narrow QRS complexes (<120 ms) and echocardiographic evidence of mechanical asynchrony. Background: Cardiac resynchronization therapy is currently recommended to advanced HF patients with prolonged QRS duration. Echocardiographic assessment of systolic mechanical asynchrony has been proven useful to predict a favorable response after CRT. Methods: A total of 102 HF patients with New York Heart Association (NYHA) functional class III or IV were enrolled. Among them, 51 had wide QRS (>120 ms) and 51 had narrow QRS (<120 ms). Tissue Doppler imaging (TDI) was employed to select patients with systolic asynchrony (increased asynchrony index) in the narrow-QRS group. Clinical and echocardiographic assessments were performed at baseline and 3 months after CRT. Results: There was a significant reduction of left ventricular (LV) end-systolic volume in both narrow (122 ± 42 cc vs. 103 ± 47 cc, p < 0.001) and wide (148 ± 74 cc vs. 112 ± 64 cc, p < 0.001) QRS groups. Improvement of NYHA functional class (both p < 0.001), maximal exercise capacity (both p < 0.05), 6-min hall-walk distance (both p < 0.01), ejection fraction (both p < 0.001), and mitral regurgitation (both p < 0.005) was also observed. In both groups, the degree of baseline mechanical asynchrony determined LV reverse remodeling to a similar extent, as shown by the superimposed regression lines. Withholding CRT for 4 weeks resulted in loss of echocardiographic benefits. Conclusions: Cardiac resynchronization therapy for HF patients with narrow QRS complexes and coexisting mechanical asynchrony by TDI results in LV reverse remodeling and improvement of clinical status. The amplitude of benefit is similar to the wide-QRS group provided that similar extent of systolic asynchrony is selected. [Copyright &y& Elsevier]