Cardiac resynchronization therapy as a therapeutic option in patients with moderate-severe functional mitral regurgitation and high operative risk.

BACKGROUND: Functional mitral regurgitation (MR) is a common finding in heart failure patients with dilated cardiomyopathy and has important prognostic implications. However, the increased operative risk of these patients may result in low referral or high denial rate for mitral valve surgery. Cardiac resynchronization therapy (CRT) has been shown to have a favorable effect on MR. Aims of this study were to (1) evaluate CRT as a therapeutic option in heart failure patients with functional MR and high operative risk and (2) investigate the effect of MR improvement after CRT on prognosis. METHODS AND RESULTS: A total of 98 consecutive patients with moderate-severe functional MR and high operative risk underwent CRT according to current guidelines. Echocardiography was performed at baseline and 6-month follow-up; severity of MR was graded according to a multiparametric approach. Significant improvement of MR was defined as a reduction ≥ 1 grade. All-cause mortality was assessed during follow-up (median 32 [range 6.0 to 116] months). Thirteen patients (13%) died before 6-months follow-up. In the remaining 85 patients, significant reduction in MR was observed in all evaluated parameters. In particular, 42 patients (49%) improved ≥ 1 grade of MR and were considered MR improvers. Survival was superior in MR improvers compared to MR nonimprovers (log rank P<0.001). Mitral regurgitation improvement was an independent prognostic factor for survival (hazard ratio 0.35, confidence interval 0.13 to 0.94; P=0.043). CONCLUSIONS: Cardiac resynchronization therapy is a potential therapeutic option in heart failure patients with moderate-severe functional MR and high risk for surgery. Improvement in MR results in superior survival after CRT.

Alterations in multidirectional myocardial functions in patients with aortic stenosis and preserved ejection fraction: a two-dimensional speckle tracking analysis.

AIMS: To identify changes in multidirectional strain and strain rate (SR) in patients with aortic stenosis (AS). METHODS AND RESULTS: A total of 420 patients (age 66.1 ± 14.5 years, 60.7% men) with aortic sclerosis, mild, moderate, and severe AS with preserved left ventricular (LV) ejection fraction [(EF), ≥50%] were included. Multidirectional strain and SR imaging were performed by two-dimensional speckle tracking. Patients were more likely to be older (P < 0.001) and at a worse New York Heart Association functional class (P < 0.001) with increasing AS severity. There was a progressive stepwise impairment in longitudinal, circumferential, and radial strain and SR with increasing AS severity (all P < 0.001). The myocardial dysfunction appeared to start in the subendocardium with mild AS, to mid-wall dysfunction with moderate AS, and eventually transmural dysfunction with severe AS. Aortic valve area, as a measure of AS severity, was an independent determinant of multidirectional strain and SR on multiple linear regressions. CONCLUSIONS: Patients with AS have evidence of subclinical myocardial dysfunction early in the disease process despite normal LVEF. The myocardial dysfunction appeared to start in the subendocardium and progressed to transmural dysfunction with increasing AS severity. Symptomatic moderate and severe AS patients had more impaired multidirectional myocardial functions compared with asymptomatic patients.

Impact of clinical and echocardiographic response to cardiac resynchronization therapy on long-term survival.

BACKGROUND: Clinical or echocardiographic mid-term responses to cardiac resynchronization therapy (CRT) may have a different influence on a long-term prognosis of heart failure patients treated with CRT. The aim of the evaluation was to establish which definition of response to CRT, clinical or echocardiographic, best predicts long-term prognosis. METHODS AND RESULTS: A total of 679 heart failure patients treated with CRT were included. All the patients underwent a complete history and physical examination and transthoracic echocardiogram prior to CRT implantation and at 6-month follow-up. The clinical and echocardiographic responses to CRT were defined based on clinical improvement (≥1 NYHA class) and LV reverse remodelling (reduction in LV end-systolic volume ≥15%) at 6-month follow-up, respectively. All the patients were prospectively followed up for the occurrence of death. The mean age was 65 ± 11 years and 79% of the patients were male. At 6-month follow-up, 510 (77%) patients showed clinical response to CRT and 412 (62%) patients showed echocardiographic response to CRT. During a mean follow-up of 37 ± 22 months, 140 (21%) patients died. Clinical and echocardiographic responses to CRT were both significantly related to all-cause mortality on univariable analysis. However, on multivariable Cox-regression analysis only echocardiographic response to CRT was independently associated with superior survival (hazard ratio: 0.38; 95% CI: 0.27-0.50; P < 0.001). CONCLUSION: In a large population of heart failure patients treated with CRT, the reduction in LV end-systolic volume at the mid-term follow-up demonstrated to be a better predictor of long-term survival than improvement in the clinical status.

Value of the surface electrocardiogram in detecting right ventricular dilatation in the presence of left bundle branch block.

Approximately 20% of patients with heart failure have left bundle branch block (LBBB) on surface electrocardiogram (ECG). In this group of patients, detection of right ventricular (RV) dilatation on standard ECG can be of clinical relevance because RV enlargement is an important prognostic marker. Consequently, the aim of this study was to evaluate diagnostic accuracy for several electrocardiographic criteria in determining significant RV dilatation in these patients. Standard 12-lead ECGs were obtained in 173 patients with heart failure and known LBBB. From the ECG, 3 criteria for RV dilatation were defined: presence of terminal positivity in lead aVR (late R wave in lead aVR), low voltage (<0.6 mV) in all extremity leads, and an R/S ratio <1 in lead V(5). In addition, all patients underwent comprehensive echocardiographic evaluation including assessment of RV dimensions. Measurements were performed blinded to electrocardiographic results. Significant RV dilatation was defined as an RV base-to-apex length ≥ 86 mm or an RV diastolic area ≥ 33 cm(2). Eighty-six patients (50%) had a late R wave in lead aVR, 36 patients (21%) had low voltage in extremity leads, and 67 patients (39%) had an R/S ratio <1 in lead V(5). An RV base-to-apex length ≥ 86 mm was present in 67 patients (39%), and 62 patients (36%) had an RV diastolic area ≥ 33 cm(2). Any combination of 2 to 3 positive criteria could predict an RV base-to-apex length ≥ 86 mm with a positive predictive value of 89% and a negative predictive value of 88%. Similarly, an RV diastolic area ≥ 33 cm(2) was predicted with a positive predictive value of 80% and a negative predictive value of 88%. In conclusion, combining 2 to 3 distinct electrocardiographic criteria allows for accurate detection of RV dilatation in patients with heart failure and LBBB.