Current patterns of beta-blocker prescription in cardiac amyloidosis: an Italian nationwide survey.

AIMS: The use of beta-blocker therapy in cardiac amyloidosis (CA) is debated. We aimed at describing patterns of beta-blocker prescription through a nationwide survey. METHODS AND RESULTS: From 11 referral centres, we retrospectively collected data of CA patients with a first evaluation after 2016 (n = 642). Clinical characteristics at first and last evaluation were collected, with a focus on medical therapy. For patients in whom beta-blocker therapy was started, stopped, or continued between first and last evaluation, the main reason for beta-blocker management was requested. Median age of study population was 77 years; 81% were men. Arterial hypertension was found in 58% of patients, atrial fibrillation (AF) in 57%, and coronary artery disease in 16%. Left ventricular ejection fraction was preserved in 62% of cases, and 74% of patients had advanced diastolic dysfunction. Out of the 250 CA patients on beta-blockers at last evaluation, 215 (33%) were already taking this therapy at first evaluation, while 35 (5%) were started it, in both cases primarily because of high-rate AF. One-hundred-nineteen patients (19%) who were on beta-blocker at first evaluation had this therapy withdrawn, mainly because of intolerance in the presence of heart failure with advanced diastolic dysfunction. The remaining 273 patients (43%) had never received beta-blocker therapy. Beta-blockers usage was similar between CA aetiologies. Patients taking vs. not taking beta-blockers differed only for a greater prevalence of arterial hypertension, coronary artery disease, AF, and non-restrictive filling pattern (P < 0.01 for all) in the former group. CONCLUSIONS: Beta-blockers prescription is not infrequent in CA. Such therapy may be tolerated in the presence of co-morbidities for which beta-blockers are routinely used and in the absence of advanced diastolic dysfunction.

The challenge of optimising ablation lesions in catheter ablation of ventricular tachycardia.

Radiofrequency catheter ablation has become an established treatment for ventricular tachycardia. The exponential increase in procedures has provided further insights into mechanisms causing arrhythmias and identification of ablation targets with the development of new mapping strategies. Since the definition of criteria to identify myocardial dense scar, borderzone and normal myocardium, and the description of isolated late potentials, local abnormal ventricular activity and decrementing evoked potential mapping, substrate-guided ablation has progressively become the method of choice to guide procedures. Accordingly, a wide range of ablation strategies have been developed from scar homogenization to scar dechanneling or core isolation using increasingly complex and precise tools such as multipolar or omnipolar mapping catheters. Despite these advances long-term success rates for VT ablation have remained static and lower in nonischemic than ischemic heart disease because of the more patchy distribution of myocardial scar. Ablation aims to deliver an irreversible loss of cellular excitability by myocardial heating to a temperatures exceeding 50°C. Many indicators of ablation efficacy have been developed such as contact force, impedance drop, force-time integral and ablation index, mostly validated in atrial fibrillation ablation. In ventricular procedures there is limited data and ablation lesion parameters have been scarcely investigated. Since VT arrhythmia recurrence can be related to inadequate RF lesion formation, it seems reasonable to establish robust markers of ablation efficacy.