Brief Report

Complete atrioventricular block after valvular heart surgery and the timing of pacemaker implantation☆

Conduction disturbances necessitating permanent pacemaker (PPM) implantation after cardiac surgery occur in 1% to 5% of patients. Previous studies have reported a low rate of late PPM dependency, but there is lack of evidence that it might be related to implantation timing. In this study, we sought to determine whether PPM implantation timing and specific conduction disturbances as indications for PPM implantation are associated with late pacemaker dependency and recovery of atrioventricular (AV) conduction.

Patients with a PPM implanted after cardiac surgery were followed in an outpatient clinic. Two outcomes were assessed: AV conduction recovery and PPM dependency, defined as the absence of intrinsic rhythm on sensing test in VVI mode at 40 bpm.

Of 15,092 patients operated between September 2008 and March 2019, 185 (1.2%) underwent PPM implantation. One hundred seventy-seven of these patients met the criteria for inclusion into this study. Follow-up data were available in 145 patients (82%). Implantation was performed at ≤6 days after surgery in 58 patients (40%) and at >6 days after surgery in 87 patients (60%). The median time from implantation to last follow-up was 890 days (range, 416-1998 days). At follow-up, 81 (56%) patients were not PPM dependent. Multivariable analysis showed that PPM implantation at ≤6 days after surgery is a predictor of being not PPM dependent (odds ratio [OR], 5.40; 95% confidence interval [CI], 2.43-12.04; P < .001) and of AV conduction recovery (OR, 4.96; 95% CI, 2.26-10.91; P < .001). Sinus node dysfunction as indication for PPM implantation was predictive of being not PPM dependent (OR, 6.59; 95% CI, 1.67-26.06; P = .007).

We recommend implanting a PPM on postoperative day 7 to prevent unnecessary implantations and avoid prolonged hospitalization.

La atención al paciente cardioquirúrgico requiere una aproximación integral y multidisciplinar para desarrollar estrategias que mejoren la seguridad y el pronóstico de los pacientes. En la fase preoperatoria destacan la implantación de medidas de prevención de las complicaciones postoperatorias más frecuentes, como la fibrilación auricular de novo o el sangrado, y la prehabilitación basada en ejercicio físico, fisioterapia respiratoria y terapia nutricional y cognitiva, especialmente en aquellos pacientes más frágiles. En la fase quirúrgica se han producido grandes avances como el desarrollo de procedimientos mínimamente invasivos, las mejoras en la preservación miocárdica, la perfusión sistémica durante la circulación extracorpórea y la protección cerebral, o la implantación de los protocolos de cirugía segura. En el postoperatorio se debe establecer un manejo hemodinámico guiado por objetivos, un correcto abordaje de los trastornos de la coagulación y el uso de analgesia multimodal que posibilite la extubación y movilización precoz de los pacientes. Por último, es clave un óptimo manejo de las complicaciones postoperatorias, entre las que destacan las arritmias, la vasoplejía, el sangrado posquirúrgico y el aturdimiento miocárdico que puede derivar en bajo gasto o, en su caso más extremo, en shock cardiogénico. Este enfoque global y el elevado nivel de complejidad hacen necesario el ingreso del paciente en unidades de alto nivel de asistencia, siendo clave el valor aportado a este proceso por los servicios de medicina intensiva para obtener unos resultados clínicos más eficaces y eficientes.

Cardio-surgical patient care requires a comprehensive and multidisciplinary approach to develop strategies to improve patient safety and outcomes. In the preoperative period, prophylaxis for frequent postoperative complications, such as de novo atrial fibrillation or bleeding, and prehabilitation based on exercise training, respiratory physiotherapy and nutritional and cognitive therapy, especially in fragile patients, stand out. There have been great advances, during the intraoperative phase, such as minimally invasive surgery, improved myocardial preservation, enhanced systemic perfusion and brain protection during extracorporeal circulation, or implementation of Safe Surgery protocols. Postoperative care should include goal-directed hemodynamic theraphy, a correct approach to coagulation disorders, and a multimodal analgesic protocol to facilitate early extubation and mobilization. Finally, optimal management of postoperative complications is key, including arrhythmias, vasoplegia, bleeding, and myocardial stunning that can lead to low cardiac output syndrome or, in extreme cases, cardiogenic shock. This global approach and the high degree of complexity require highly specialised units where intensive care specialists add value and are key to obtain more effective and efficient clinical results.

A significant percentage of patients who acutely develop high-grade atrioventricular block after valve surgery will ultimately recover, yet the ability to predict recovery is limited. The purpose of this analysis was to evaluate the cost-effectiveness of two different management strategies for the timing of permanent pacemaker implantation for new heart block after valve surgery.

A cost-effectiveness model was developed using costs and probabilities of short- and long-term complications of pacemaker placement, short-term atrioventricular node recovery, intensive care unit stays, and long-term follow-up. We aggregated the total expected cost and utility of each option over a 20-y period. Quality-adjusted survival with a pacemaker was estimated from the literature and institutional patient-reported outcomes. Primary decision analysis was based on an expected recovery rate of 36.7% at 12 d with timing of pacemaker implantation: early placement (5 d) versus watchful waiting for 12 d.

A strategy of watchful waiting was more costly ($171,798 ± $45,695 versus $165,436 ± $52,923; P < 0.0001) but had a higher utility (9.05 ± 1.36 versus 8.55 ± 1.33 quality-adjusted life years; P < 0.0001) than an early pacemaker implantation strategy. The incremental cost-effectiveness ratio of watchful waiting was $12,724 per quality-adjusted life year. The results are sensitive to differences in quality-adjusted survival and rates of recovery of atrioventricular node function.

Watchful waiting for pacemaker insertion is a cost-effective management strategy compared with early placement for acute atrioventricular block after valve surgery. Although this is cost-effective from a population perspective, clinical risk scores predicting recovery will aid in personalized decision-making.

Postoperative permanent pacemaker implantation (PPI) after conventional aortic valve replacement (AVR), due to new-onset severe conduction system disorders, is required in approximately 7% of patients. This study investigated the need for PPI after AVR with conventional stented Perimount Magna compared with the Freedom SOLO (FS) stentless valve (Sorin Group, Saluggia, Italy), now LivaNova plc (London, UK) that uses a strictly supra-annular, subcoronary running suture implantation technique, sparing the vulnerable interleaflet triangles in the region of the septum membranaceum.

A total of 413 consecutive patients (71.4±9.2 yrs, 178 [43.1%] female) underwent isolated AVR using the stented Perimount Magna (n=264) or the stentless FS (n=149) bioprosthesis. Propensity score weighted analysis was used to account for patient-specific and procedural-specific variables, and to identify the prosthesis-specific need for early postoperative PPI within 30 days of AVR.

Twenty (20) patients required PPI, which was associated with longer intensive care unit (2.1±1.7 vs 1.5±3.0 days, p<0.001) and overall hospital stays (13.8±5.2 vs 10.7±5.3 days, p<0.001) compared with no PPI. Propensity weighted logistic regression including cross-clamp times identified that use of the stented Perimount Magna was associated with increased need for PPI, as compared with the FS, with an odds ratio 5.8 (95% CI, 1.09–30.76; p=0.039).

After corrections for all plausible confounders, AVR with the stented Perimount valve was associated with an odds ratio of almost 6 for an increased early postoperative need for pacemaker implantation compared with the FS stentless valve. This finding can be explained by the conventional implantation technique, which is potentially associated with mechanical trauma to the conducting system.

The development of complete AV block and the need for pacemaker implantation (PM) is the most frequent complication after Transaortic valve replacement (TAVR). In other PM clinical contexts, a higher percentage of ventricular stimulation has been associated with worse prognosis. The objective was to study the existence of predictors of PM dependence.

We identified 96 consecutive patients who had received a PM post-TAVR (all Core-Valve). We retrospectively analyzed this cohort with the aim of identifying predictors of a high and very high percentage of ventricular pacing (VP), PM dependency and survival.

The mean age was 82.3 years, with a mean logistic EuroSCORE of 17.1, 53% were women and 12% of patients had LVEF < 50%. The indication was complete AV block in 40.5%, and LBBB in 59.5%. Mean survival was 62.7 months, IQR [54.4–71]. The only independent predictor of mortality was the pre-TAVR logistic Euro-SCORE (RR = 1,026, p = 0.033), but not LVEF < 50%, VP > 50%, VP > 85% or PM dependence. In 73 patients PM rhythm was documented at the end of follow-up. Of these, 14 (19.2%) were considered dependent, and 37 (50.7%) presented VP > 50%. The post-TAVR complete AV block recovery rate was 67.8%. In multivariate analysis, female sex (HR = 5.6, p = 0.005), and indication of complete AV block vs. LBBB (HR = 15.7, p = 0.017) were independently associated with PM dependency.

Female sex and indication due to complete AV block were independent predictors of PM dependency during follow up. In our series of patients with mostly normal LVEF, a high percentage of stimulation does not influence prognosis.