Permanent pacemaker dependency in patients with new left bundle branch block and new first degree atrioventricular block after transcatheter aortic valve implantation

Conduction disorders with need for permanent pacemaker (PPM) implantation remain frequent complications after transcatheter aortic valve implantation (TAVI). Up to 22% of PPM after TAVI are implanted for new onset left bundle branch block (LBBB) and atrioventricular block (AVB) I. However, clinical benefit and predictors of ventricular pacing in TAVI patients receiving PPM for this indication remain unclear. We retrospectively evaluated pacemaker interrogation data of patients who received a PPM post TAVI for new LBBB and new AVB I. The primary endpoint of this study was relevant ventricular pacing (ventricular pacing rate: Vp ≥ 1%) at the first outpatient pacemaker interrogation. Secondary endpoints were predictors for relevant ventricular pacing. At the first pacemaker interrogation (median follow up at 6.23 [2.8–14.8] months), median ventricular pacing frequency was 1.0% [0.1–17.8]. Out of 61 patients, 36 (59%) had Vp rates ≥ 1%. Patients with frequent ventricular pacing showed longer QRS duration (155 ms ± 17 ms vs. 144 ms ± 18 ms, p = 0.018) at the time of PPM implantation and were less likely treated with a balloon-expandable Edwards Sapiens Valve (39% vs. 12%, p = 0.040). Our findings suggest that the majority of patients with new LBBB and new AVB I after TAVI show relevant ventricular pacing rates at follow up. Further prospective studies are necessary to identify patients at higher risk of pacemaker dependency.

607 Comparison of incidence and predictors of new left bundle branch block and permanent pacemaker implantation in a large multicentre contemporary TAVI registry using the Evolut R/pro system vs. the accurate neo valve

Aims Conduction disorders and permanent pacemaker implantation (PPI) continue to be an important issue in patients who undergo transcatheter aortic valve implantation (TAVI). The aim of this study was to investigate the incidence and clinical outcomes of new left bundle branch block (LBBB) and PPI after TAVI in a comparison between two self-expandable supra-annular transcatheter valves. Methods and results We report the data from an international, retrospective registry including 3862 consecutive patients who underwent TAVI with two self-expanding transcatheter heart valves (Medtronic Evolut R/PRO and Boston ACURATE neo). Patients with pre-existing left or right bundle branch block, any atrioventricular blocks or previous pacemaker implantation were excluded. Finally, we performed a propensity score matched analysis (PSM) to match the patients and overcome pre-procedural differences reaching 427 couples. New-onset Left Bundle Branch Block (LBBB) occurred with a rate of 13.1% (56/427) in the ACURATE group and 18.7% (80/427) in the Evolut group (P = 0.031). The incidence of new permanent pacemaker implantation was 16.4% (70/427) in the Evolut group and 6.8% (29/427) in the ACURATE group, respectively (P < 0.001). In the multivariate regression analysis, we found the valve recapture [odds ratio (OR): 4.66, 95% confidence interval (CI): 1.08–23.75, P = 0.042] as significant predictors for LBBB, and male sex (OR: 1.59, CI: 1.03–2.46, P = 0.036), ACURATE valve (OR: 0.34, CI: 0.20–0.57, P < 0.001) and post-procedure LBBB (OR: 4.38, CI: 2.78–6.85, P < 0.001) for PPI. Conclusions In our large multi-centre contemporary cohort of patients, new LBBB and PPI occurred more frequently in patients following TAVI with Evolut R/PRO vs. ACURATE valve. However, the choice of the valve seemed to influence only the rate of pacemaker implantation and not the incidence of new LBBB. Further data is required to clarify the impact of valve design on conduction abnormalities.

539 Frequency related left bundle branch block as cause of chest pain: ‘painful LBBB syndrome’

Aims A 47-years-old man presented to our cardiology ambulatory due to sudden chest pains, mainly on exertion. His only relevant cardiovascular risk factor was a familiarity for coronaropathy. In 2013 he had undergone a coronary angiography which was negative for stenotic lesions. Since then he was treated with beta-blockers and Ivabradine with mild improvement of the pain. Methods and results While his previous Holter-ECG reported sinus rhythm [heart rate (HR) 60 b.p.m.] and no alterations of atrioventricular nor of interventricular conduction, his ECG during his examination in our ambulatory showed sinus rhythm (HR 80 b.p.m.), normal atrioventricular conduction but presence of complete left bundle branch block. We therefore performed an ergometric test. His baseline ECG (HR around 65 b.p.m.), at the start of the test, showed no left bundle branch block and the QRS complex was narrow. During the test, at the heart rate of around 85 b.p.m., the ECG showed a complete left bundle branch block. At the same time the patient complained of typical chest pain. The ergometric test was submaximal as it was stopped at the beginning of the third Bruce stage due to the patient’s chest pain. No ST segment alterations were found. During the recovery phase, we noted that the left bundle branch block disappeared when the heart rate was below 75 b.p.m. A new coronary angiography was performed and again it showed no stenotic lesion. We therefore concluded our diagnostic workup and diagnosed a frequency related ‘painful left bundle branch block syndrome’. Conclusions ‘Painful left bundle branch block syndrome’ is defined as the presence of typical chest pain together with left bundle branch block, in the absence of signs of myocardial ischaemia. The pain improves once the conduction defect disappears. The mechanism of the syndrome is not known although it seems to be related to dyssynchrony of the myocardium. It may often be frequency related.