Strategy to achieve mitral isthmus flutter ablation by radiofrequency: the SHERIFF plan.

BACKGROUND: Achieving mitral isthmus (MI) block can be challenging. This prospective study evaluated the feasibility and efficacy of a systematic strategy comprising three consecutive steps to achieve MI block. METHODS: Twenty consecutive patients (mean (± SD) age 71.4 ± 6.98 years) undergoing ablation of perimitral atrial tachycardia (PMAT) between December 2019 and November 2021 were included. MI was ablated using a systematic strategy comprising up to three consecutive steps: (1) endocardial ablation from the superolateral mitral annulus to the left pulmonary veins; (2) additional epicardial ablation in the coronary sinus (CS) on the opposite side of the endocardial line; and (3) ablation of early activation sites between endocardial and epicardial breakthroughs. RESULTS: MI block was successfully achieved in 19/20 patients (95%). MI block after endocardial radiofrequency ablation alone (step 1) was observed in 7/20 patients (35%). Epicardial ablation within the CS on the other side of the endocardial line (step 2) resulted in bidirectional MI block in three more patients. Endocardial ablation of epicardial conduction was successful for nine additional patients (95% success). At the 12-month follow-up, five patients (25%) displayed recurrence of arrhythmia after a single procedure. One patient had electrical cardioversion for persistent atrial fibrillation. Four patients had a redo procedure for left atrial flutter and only two patients (10%) had conduction across the MI and showed recurrence of PMAT. No complications occurred. CONCLUSIONS: The three-step ablation strategy resulted in a high rate of acute and durable MI block. PMAT recurrence after a single procedure was 10% at 1-year follow-up.

Doppler echocardiography for surveillance of acute cardiac allograft rejection: a 28-year single-center experience.

Background: Endomyocardial biopsies (EMB) are recommended for the detection of acute cardiac rejection (ACR) despite limited sensitivity. We report the long-term post-transplant results of Doppler echocardiography as a noninvasive alternative of routine EMB. Methods: Two cohorts of heart transplantation (HT) recipients were chronologically defined as follows: the Dual Monitoring Cohort (DMC) from January 1990 to December 1997 included patients who underwent routine EMB and Doppler echocardiography within 24 hours for ACR surveillance; and the "Echo-First Cohort" (EFC), including patients transplanted from January 1998 to December 2018 with Doppler echocardiography as first-line approach for ACR surveillance. Echocardiographic measurements of interest were collected: early diastolic (E) wave peak velocity; pressure half time (PHT) and isovolumetric relaxation time (IVRT). Post-transplant outcomes were reviewed and the Kaplan-Meier approach was used for survival estimates. Inter-operator variability for ultrasound measurements was investigated. Data were collected from medical records from January 2019 to December 2020. Results: A total of 228 patients were included, 99 patients in the DMC and 129 in the EFC. Overall, 5-, 10- and 15-year survival rates were 65.4%, 55.5% and 44.1% respectively, without any significant difference between the two cohorts (log rank test, P=0.71). Echocardiography variables and EMB findings were associated with a mean area under the receiver operating characteristic curve (AUC-ROC) of 0.73 [95% confidence interval (CI): 0.54-0.91], 0.74 (95% CI: 0.54-0.94) and 0.75 (95% CI: 0.57-0.94) respectively for E wave, PHT and IVRT. IVRT and PHT were significantly decreased, and E wave significantly increased, in case of histologically proven ACR. Inter-operator variability was not significant for E wave and IVRT measurements (P=0.13 and 0.30 respectively). Conclusions: Doppler echocardiography as a first-line method for surveillance of ACR did not impair long-term results after HT. These findings suggest that this non-invasive approach might be a reasonable alternative to systematic EMB, limiting risk and improving the quality of life.

Causes and predictors of mortality after transcatheter mitral valve implantation in patients with severe mitral annulus calcification.

OBJECTIVES: To evaluate the causes and predictors of mortality after valve-in-mitral annulus calcification (MAC) transcatheter mitral valve implantation (TMVI). BACKGROUND: Conventional surgical mitral valve replacement is associated with a high risk in patients with mitral valve disease associated with severe MAC. In this population, TMVI may be an attractive alternative option. However, its prognostic factors are poorly understood. METHODS: All patients undergoing valve-in-MAC TMVI from 2013 to 2018 in our center were included. Indication for TMVI relied on the judgment of the local heart team. Patients were followed at 30 days and 1 year. RESULTS: A total of 34 patients underwent valve-in-MAC TMVI. The mean age was 79 ± 11 years and 73% of patients were women. Their mean EuroSCORE 2 was 8 ± 7%. The transseptal approach was used in 79% of patients and a hybrid transatrial in 29%. Balloon expandable transcatheter heart valves were used in all the patients. Technical success was achieved in 76% of the patients. Thirty-day and 1-year all-cause mortality rates were 14.7% and 32.4%, respectively. The main two causes of 1-year mortality were congestive heart failure (8.8%) and infective endocarditis (5.9%). In multivariate analysis, the only predictor of 1-year mortality was the presence of periprothetic mitral regurgitation grade 2 (HR, 5.69; 95%CI, 1.59-27.88, p = 0.032). CONCLUSION: Early and mid-term mortality remains high after valve-in-MAC TMVI and seems to be associated with the presence of paravalvular mitral regurgitation. However, whether the latter is a prognostic factor or marker remains to be determined to improve clinical outcomes in this high-risk population.