Long-term clinical and echocardiographic outcomes of Mitraclip therapy in patients nonresponders to cardiac resynchronization.

OBJECTIVES: This study deals with clinical and echocardiographic outcomes in cardiac resynchronization therapy (CRT) nonresponders patients undergoing Mitraclip procedure. BACKGROUND: Functional mitral regurgitation (FMR) occurs in approximately one-third of heart failure (HF) patients. Resynchronization therapy may correct FMR in patients with HF; however, significant FMR persists in 20-25% of CRT patients. METHODS: All patients included were previously treated with CRT for at least 6 months and remained classified as New York Heart Association (NYHA) functional class III or IV despite optimal medical therapy; the echocardiographic assessment showed lack of decrease of the left ventricular end-systolic volume (LVESV) of at least 10% and residual moderate-to-severe or severe FMR. Clinical and echocardiographic follow-up was scheduled at 1, 3, 6, and 12 months after Mitraclip implantation, and every 6 months thereafter. RESULTS: Thirty patients fulfilled inclusion criteria. Before Mitraclip implantation NYHA class was III in 83% and IV in 17% of patients; after CRT no patient experienced an improvement in FMR. There was a significant improvement in NYHA class from baseline to 6 months, which remained sustained at 12 and 24 months. The degree of FMR significantly improved from baseline to 6 months and from 6 to 12 months. There was left ventricle remodeling with significant reduction of LVESV and an increase of left ventricle ejection fraction at 6 and 12 months, while the opposite trend was noted between 12 and 24 months CONCLUSION: Treatment of moderate to severe FMR in CRT nonresponder is feasible, safe, and reasonably effective in reducing cardiac symptoms.

Ventricular arrhythmias in aortic valve stenosis before and after transcatheter aortic valve implantation.

AIMS: Transcatheter aortic valve implantation (TAVI) is a therapeutic treatment for patients with severe aortic stenosis (AS) at high surgical risk. Although the procedure is associated with a reduction in total mortality, there are no data regarding changing in the incidence of premature ventricular contractions (PVCs) and ventricular arrhythmias (VAs) after TAVI. The aim of this study was to assess the incidence of VAs before and after TAVI. METHODS AND RESULTS: We enrolled 237 patients who underwent TAVI at our centre. Ninety-one patients were excluded for the following reasons: presence of prior permanent pacemaker (PPM) (n = 20), new PPM implant after TAVI (n = 48), death during the follow-up period (n = 16), and lost at follow-up (n = 7). Finally, 146 patients were included in our analysis. The presence of VAs was evaluated in all patients recording a 24 h Holter monitoring before the procedure and after 1 and 12 months. Ventricular arrhythmias were classified according to a modified Lown grading system. Before the procedure, isolates PVCs (grade 1-2 of Lown grading system) were present in 34.9% of patients (n = 51). Complex PVCs (grade 3-4a-4b of Lown grading system) were present in 48.6% of the population (multifocal PVCs in 32 patients, 21.9%; pairs in 25 patients, 17.1%; ventricular tachycardia in 14 patients, 9.6%). One month after the procedure, we observed statistically significant incidence decrease of arrhythmias of grade 3 (from 21.9 to 17.1%) and grade 4 (pairs from 17.1 to 12.3%; ventricular tachycardia from 9.6 to 4.8%). After 12 months, there was a further significant reduction in the frequency and severity of PVCs. In particular, 45.8% of patients had isolates PVCs (<30 in all given hours of monitoring in 45 patients, 30.8%; higher than 30 in any hour of monitoring in 22 patients, 15%) while the frequency of complex arrhythmias was reduced to 16.4% (multifocal PVCs in 13 patients, 9%; couplets 8 patients, 5.5% and ventricular tachycardia in 3 patients, 2.0%). The difference was statistically significant (P < 0.01). CONCLUSION: This study indicates that VAs are common in patients with AS. We observed a significant decrease in the incidence and severity of PVCs since the first month after TAVI. Furthermore, after 1 year follow-up there was a further and significant reduction in the frequency of complex PVCs. This may be related to the benefits determined by valve replacement on left ventricular function.

Intraoperative defibrillation threshold testing during implantable cardioverter-defibrillator insertion: do we really need it?

BACKGROUND: The assessment of defibrillation efficacy using a safety margin of 10 J has long been the standard of care for insertion of implantable cardioverter-defibrillator (ICD), but physicians are concerned about complications related to induction test. Therefore, the need for testing has been recently questioned. The aim of our study was to assess the impact of defibrillation threshold (DFT) testing of ICD on the efficacy of ICD therapy. METHODS: We analyzed data obtained from follow-up visits of 122 consecutive patients who underwent ICD implantation at our institute from April 1996 to June 2008, with (n = 42) or without (n = 80) DFT testing. Patients in the DFT group were less likely to be men (83.3% vs 96.3%, P < .031) than those in the non-DFT group. Conversely, the 2 groups were similar in age, left ventricular ejection fraction at baseline, functional class, and underlying cardiovascular disease. Results during a 12-month follow-up, 13 (31.0%) and 30 (37.5%) ventricular tachyarrhythmic episodes were recorded in the DFT and non-DFT groups, respectively (P = .472). Antitachycardia pacing (ATP) terminated most of episodes, reducing the need of defibrillation at 7.7% in the DFT group and 3.3% in the non-DFT group (P = .533). Similar percentages of inappropriate ATP interventions (7.1% vs 3.8%, P = .413) and shock deliveries (2.4% vs 5.0%, P = .659) were recorded between DFT and non-DFT groups. CONCLUSIONS: At 1-year follow-up, the performance of DFT testing does not seem to add any significant efficacy advantage in patients undergoing ICD implantation. Prospective randomized trials and long-term follow-up are warranted to clarify whether routine DFT testing may be safely abandoned leading to a revision of current guidelines.

Functional and clinical implications of cardiac resynchronization therapy on outcomes of diabetic patients with heart failure.

AIMS: To compare functional and structural changes of the left ventricle and long-term clinical outcomes in diabetic and nondiabetic patients with heart failure undergoing cardiac resynchronization therapy (CRT). METHODS: Sixty-eight patients with heart failure undergoing CRT were included: 18 were diabetic patients and 50 nondiabetic patients. The CRT eligibility was established by echocardiographic assessments. RESULTS: CRT improved ventricular geometry and dyssynchrony in both diabetic and nondiabetic patients, with no significant difference in the magnitude of the effects on the left ventricular function. Over a median follow-up of 30.6 ± 6.2 months, there were no significant differences in the rates of any cause death (16.7 vs. 14.0%, P = 0.72), cardiac death (11.1 vs. 8.0%, P = 0.65) and heart rehospitalization (5.6 vs. 6.0%, P = 1.0), between diabetic and nondiabetic patients, respectively. Diabetes was not found to be an independent factor associated with worse clinical outcome. CONCLUSION: Resynchronization therapy provided significant functional and hemodynamic improvements in both diabetic and nondiabetic patients. Long-term prognosis in heart failure patients with diabetes was comparable with that in those without diabetes.