Aortic Valve Calcification as a Predictor of Post-Transcatheter Aortic Valve Replacement Pacemaker Dependence.

Atrioventricular block requiring permanent pacemaker (PPM) implantation is a common complication of transcatheter aortic valve replacement (TAVR). The mechanism of atrioventricular (AV) block during TAVR is not fully understood, but it may be due to the mechanical stress of TAVR deployment, resulting in possible injury to the nearby compact AV node. Aortic valve calcification (AVC) may worsen this condition and has been associated with an increased risk for post-TAVR PPM implantation. We performed a retrospective analysis to determine if AVC is predictive for long-term right ventricular (RV) pacing in post-TAVR pacemaker patients at 30 days. A total of 262 consecutive patients who underwent TAVR with a balloon-expandable valve were analyzed. AVC data were derived from contrast-enhanced computed tomography and characterized by leaflet sector and region. A total of 25 patients (11.1%) required post-TAVR PPM implantation. Seventeen patients did not require RV pacing at 30 days. Nine of these 17 patients had no RV pacing requirement within 10 days. The presence of intra-procedural heart block (P = 0.004) was the only significant difference between patients who did not require PPM and those who required PPM but they were not RV pacing-dependent at 30 days. Non-coronary cusp (NCC) calcium volume was significantly higher in patients who were pacemaker-dependent at 30 days (P = 0.01) and a calcium volume of > 239.2 mm3 in the NCC was strongly predictive of pacemaker dependence at 30 days (area under the curve (AUC) = 0.813). Pre-existing right bundle branch block (RBBB) (odds ratio (OR) 105.4, P = 0.004), bifascicular block (OR 12.5, P = 0.02), QRS duration (OR 70.43, P = 0.007) and intra-procedural complete heart block (OR 12.83, P = 0.03) were also predictive of pacemaker dependence at 30 days. In patients who required PPM after TAVR, quantification of AVC by non-coronary leaflet calcium volume was found to be a novel predictor for RV pacing dependence at 30 days. The association of NCC calcification and PPM dependence may be related to the proximity of the conduction bundle to the non-coronary leaflet. Further studies are necessary to improve risk prediction for long-term RV pacing requirements following TAVR.

Sharma E ，McCauley B ，Ghosalkar DS ，Atalay M ，Collins S ，Parulkar A ，Sheikh W ，Ahmed MB ，Chu A ... -  《-》

Predictors of right ventricular pacing and pacemaker dependence in transcatheter aortic valve replacement patients.

Sharma E ，Chu AF 《-》

A Highly Predictive Risk Model for Pacemaker Implantation After TAVR.

This study sought to develop a robust and definitive risk model for new permanent pacemaker implantation (PPMI) after SAPIEN 3 (third generation balloon expandable valve) (Edwards Lifesciences, Irvine, California) transcatheter aortic valve replacement (third generation balloon expandable valve TAVR), including calcification in the aortic-valvular complex (AVC). The association between calcium in the AVC and need for PPMI is poorly delineated after third generation balloon expandable valve TAVR. At Cedars-Sinai Heart Institute in Los Angeles, California, a total of 240 patients with severe aortic stenosis underwent third generation balloon expandable valve TAVR and had contrast computed tomography. AVC was characterized precisely by leaflet sector and region. The total new PPMI rate was 14.6%. On multivariate analysis for predictors of PPMI, pre-procedure third generation balloon expandable valve TAVR, right bundle branch block (RBBB), shorter membranous septum (MS) length, and noncoronary cusp device-landing zone calcium volume (NCC-DLZ CA) were included. Predictive probabilities were generated using this logistic regression model. If 3 pre-procedural risk factors were present, the c-statistic of the model for PPMI was area under the curve of 0.88, sensitivity of 77.1%, and specificity of 87.1%; this risk model had high negative predictive value (95.7%). The addition of the procedural factor of device depth to the model, with the parameter of difference between implantation depth and MS length, combined with RBBB and NCC-DLZ CA increased the c-statistic to 0.92, sensitivity to 94.3%, specificity to 83.8%, and negative predictive value to 98.8% CONCLUSIONS: By using a precise characterization of distribution of calcification in the AVC in a single-center, retrospective study, NCC-DLZ CA was found to be an independent predictor of new PPMI post-third generation balloon expandable valve TAVR. The findings also reinforce the importance of short MS length, pre-existing RBBB, and ventricular implantation depth as important synergistic PPMI risk factors. This risk model will need validation by future prospective multicenter studies.

Maeno Y ，Abramowitz Y ，Kawamori H ，Kazuno Y ，Kubo S ，Takahashi N ，Mangat G ，Okuyama K ，Kashif M ，Chakravarty T ，Nakamura M ，Cheng W ，Friedman J ，Berman D ，Makkar RR ，Jilaihawi H ... -  《-》

Conduction Abnormalities and Permanent Pacemaker Implantation After Transcatheter Aortic Valve Replacement Using the Repositionable LOTUS Device: The United Kingdom Experience.

The authors report the incidence of pacemaker implantation up to hospital discharge and the factors influencing pacing rate following implantation of the LOTUS bioprosthesis (Boston Scientific, Natick, Massachusetts) in the United Kingdom. Transcatheter aortic valve replacement (TAVR) is associated with a significant need for permanent pacemaker implantation. Pacing rates vary according to the device used. The REPRISE II (Repositionable Percutaneous Replacement of Stenotic Aortic Valve Through Implantation of Lotus Valve System) trial reported a pacing rate of 29% at 30 days after implantation of the LOTUS device. Data were collected retrospectively on 228 patients who had the LOTUS device implanted between March 2013 and February 2015 across 10 centers in the United Kingdom. Twenty-seven patients (12%) had pacemakers implanted pre-procedure and were excluded from the analysis. Patients were aged 81.2 ± 7.7 years; 50.7% were male. The mean pre-procedural QRS duration was 101.7 ± 20.4 ms. More than one-half of the cohort (n = 111, 55%) developed new left bundle branch block (LBBB) following the procedure. Permanent pacemakers were implanted in 64 patients (32%) with a median time to insertion of 3.0 ± 3.4 days. Chief indications for pacing were atrioventricular (AV) block (n = 46, 72%), or LBBB with 1st degree AV block (n = 11, 17%). Amongst those who received a pacemaker following TAVR the pre-procedural electrocardiogram findings included: No conduction disturbance (n = 41, 64%); 1st degree AV block (n = 10, 16%); right bundle branch block (n = 6, 9%) and LBBB (n = 5, 8%). LBBB (but not permanent pacemaker) occurred more frequently in patients who had balloon aortic valvuloplasty before TAVR (odds ratio [OR]: 1.25; p = 0.03). Pre-procedural conduction abnormality (composite of 1st degree AV block, hemiblock, right bundle branch block, LBBB) was independently associated with the need for permanent pacemaker (OR: 2.54; p = 0.048). The absence of aortic valve calcification was also associated with a higher pacing rate (OR: 0.55; p = 0.031). Multivariate regression analysis did not show an independent association between depth of implant, valve oversizing, balloon post-dilatation, and the need for pacing post-procedure. Following implantation of the repositionable LOTUS valve, 55% of patients developed LBBB and 32% of patients required a pacemaker during their index hospital admission. Patients with pre-procedural conduction disturbance and non-calcified aortic valves were more likely to need pacing. No other anatomic features were identified with increased pacing requirement with the LOTUS device.

Rampat R ，Khawaja MZ ，Hilling-Smith R ，Byrne J ，MacCarthy P ，Blackman DJ ，Krishnamurthy A ，Gunarathne A ，Kovac J ，Banning A ，Kharbanda R ，Firoozi S ，Brecker S ，Redwood S ，Bapat V ，Mullen M ，Aggarwal S ，Manoharan G ，Spence MS ，Khogali S ，Dooley M ，Cockburn J ，de Belder A ，Trivedi U ，Hildick-Smith D ... -  《-》

Loss of His-bundle and Right Ventricular Septal Capture Following Transcatheter Aortic Valve Replacement-A Case Report.

Conduction abnormalities following transcatheter aortic valve replacement (TAVR) are common. High-grade atrioventricular block (AVB) and new-onset left bundle branch block remain the most reported. These often require the placement of a permanent pacemaker (PPM). His-bundle (HB) pacing is increasingly being utilized as the preferred mode of ventricular pacing due to its more physiologic ventricular activation. In this case report, we present a case of a patient who developed loss of HB capture and experienced an increase in the local right ventricular (RV) capture threshold after TAVR that led to unrecognized intermittent loss of ventricular capture and symptoms. An 80-year-old man with severe aortic stenosis presented with symptomatic bradycardia due to typical atrial flutter (AFL) with a high-grade AVB and an underlying right bundle branch block. He underwent placement of a dual-chamber PPM (Medtronic, Inc., Minneapolis, MN, USA) with a HB pacing lead. HB mapping demonstrated a normal H-V interval, and the lead was fixated with non-selective HB capture. The R-waves measured 2.8 mV, the pacing impedance was 544 Ω, and the non-selective HB and local RV capture threshold was 0.5 V @ 1 ms. He underwent AFL ablation, and his atrial leads were normal. He subsequently underwent successful TAVR with a 29-mm Sapien 3 valve (Edwards Lifesciences, Irvine, CA, USA). Post-TAVR, PPM interrogation showed a loss of HB capture with a left bundle paced QRS morphology. Following discharge, he presented with stroke-like symptoms and was noted to have intermittent loss of RV capture with complete heart block (CHB) and a slow ventricular escape rhythm. PPM interrogation revealed an elevated pacing threshold, and his RV output was gradually increased to a maximum output of 7.5 V @ 1.5 ms. He also developed a fever and was found to have enterococcal bacteremia. Transesophageal echocardiography demonstrated vegetations on his prosthetic valve and pacemaker lead, without a perivalvular abscess. He underwent explantation of the pacemaker system and insertion of a temporary PPM. After intravenous antibiotic therapy with negative blood cultures, he underwent re-implantation of a new right-sided dual-chamber PPM, and an RV pacing lead was placed into the RV outflow tract. HB pacing is becoming the preferred mode of physiologic ventricular pacing. This case illustrates the potential risks of the TAVR procedure in patients with existing HB pacing leads. We observed a loss of HB capture and the development of CHB due to traumatic injury to the HB distal to the HB pacing lead after TAVR placement together with an increase in the local RV capture threshold. The depth of TAVR placement is an important aspect of the TAVR procedure that determines the risk of developing CHB and may also affect the HB and local RV pacing thresholds post-procedure.

Asreb A ，Ahn J 《-》