Khalil, Fouad

Abstract Background Renal dysfunction is a major determinant of outcomes after heart transplantation (HT). While baseline renal impairment and post-HT dialysis are known predictors of mortality, the prognostic impact of sustained pre-HT renal decline in patients bridged with durable left ventricular assist devices (LVADs) remains unclear. Methods We conducted a retrospective, multicenter cohort study using the United Network for Organ Sharing (UNOS) registry to identify adult patients who underwent HT following durable LVAD support between 2009 and 2024. Sustained renal decline was defined as a ≥40% reduction in estimated glomerular filtration rate (eGFR) from listing to HT. Multivariable logistic regression identified predictors of renal decline and post-HT dialysis,while Cox proportional hazards models assessed the impact on post-HT mortality. Results Among 10,454 eligible patients, 624 (6.0%) experienced sustained renal decline during LVAD bridging. Compared with patients without renal decline, affected patients had longer waitlist durations (median 297 vs. 197 days; p<0.001), lower eGFR at HT (42.0 vs. 70.6 mL/min/1.73 m²; p<0.001), and higher rates of post-HT dialysis (23.7% vs. 12.8%; p<0.001). Independent predictors of sustained renal decline included longer waitlist time, perioperative blood transfusions, while the use of HeartMate 3 LVAD was protective. Sustained renal decline was independently associated with increased risk of post-HT dialysis (adjusted odds ratio [aOR] 2.64) and all-cause mortality (adjusted hazard ratio [aHR] 1.16),with post-HT dialysis strongly predicting mortality (aHR 3.48). Conclusions Sustained renal deterioration while awaiting HT is a significant predictor of post-HT dialysis and mortality in LVAD-bridged patients. Incorporating renal trajectory into risk stratification may enhance candidate selection and promote perioperative renal protection strategies.

Background Pulmonary hypertension (PH) and sensitization adversely affect heart transplant outcomes. Although left ventricular assist devices may reduce PH, they can increase sensitization. We examined the impact of sensitization on heart transplant outcomes in left ventricular assist device‐bridged patients and whether precapillary PH modifies this effect. Methods Adults bridged to heart transplant with an left ventricular assist device between 2005 and 2020 were identified from the United Network for Organ Sharing database. Patients with available panel‐reactive antibody (PRA) and hemodynamic data were included. Associations between PRA and survival and treated rejection were analyzed. Results Among 2469 patients, 1053 had precapillary PH (pulmonary vascular resistance [PVR] >2 Wood units [WU]) and 1416 had PVR ≤2 WU. Elevated PRA (>10%) occurred in 566 patients (24.8% with PVR >2 WU; 21.5% with PVR ≤2 WU). Overall, PRA >10% was associated with increased mortality (adjusted hazard ratio [aHR], 1.28 [95% CI, 1.04–1.58], P =0.022), driven by patients with PVR >2 WU (aHR, 1.82 [95% CI, 1.34–2.50], P <0.001), with no association in those with PVR ≤2 WU (aHR, 0.99 [95% CI, 0.47–1.32], P =0.92). PRA >10% was also associated with treated rejection overall (adjusted odds ratio [aOR], 1.41 [95% CI, 1.09–1.82], P =0.008), confined to the PVR >2 WU group (aOR, 1.87 [95% CI, 1.26–2.76], P =0.002) and absent in the PVR ≤2 WU group (aOR, 1.13 [95% CI, 0.80–1.59], P =0.49). Conclusions Elevated PRA predicts worse outcomes in LVAD‐bridged transplant recepients with precapillary PH, but not in those without precapillary PH.

ABSTRACTIntroductionPulsed‐field ablation (PFA) is a novel and effective modality for ablation in patients with atrial fibrillation (AF). Available case reports and small series showed promising results in patients with congenital heart disease. However, PFA ablation in Fontan patients has not been reported yet.Methods and ResultsWe present a 35‐year‐old patient with a history of Fontan palliation for hypoplastic left heart who underwent successful ablation for AF with PFA. We describe procedure characteristics and illustrate the potential benefits of PFA in this patient population.ConclusionWe present a case of PFA for AF in Fontan palliation. PFA was feasible and successful in our case. Long‐term outcomes are yet to be determined.

Abstract Background It has been hypothesized that combined heart and kidney transplantation (HKT) may lead to immune modulation and attenuation of cardiac allograft vasculopathy (CAV) progression. Sirolimus (SRL) has been shown to mitigate the progression of CAV and confer renal protection. With the increasing use of SRL as primary immunosuppression in heart transplant (HT) recipients, the effect of HKT on CAV progression compared to HT-only remains undetermined. Purpose We sought to investigate the patterns of conversion from calcineurin inhibitors (CNI) to SRL, and its impact on CAV progression and outcomes in HKT compared to HT-only in a cohort with frequent use of SRL as primary immunosuppression. Methods A cohort of 302 patients who underwent either HT only (n=262) or combined HKT (n=40) was analyzed. CAV progression was assessed by measuring the delta (Δ) annual change in plaque volume (PV) normalized to vessel length (PV/VL in mm3/mm) and plaque index (PI) (%) (calculated as the PV to VV ratio) between baseline and last follow-up coronary intravenous ultrasound (IVUS). Clinical adverse outcomes included all-cause death and CAV-associated events. Secondary outcomes included differences in renal function and incidence of SRL-associated proteinuria (defined as Δ urine protein ≥300 mg/24 h at 1 year after conversion to SRL) between HT-only and HKT recipients. Results Overall, 217 (72%) patients were converted from CNI to SRL as primary immunosuppression. HT recipients were more likely to be converted to SRL than combined HKT recipients (74% vs. 55%, P=0.01). HKT was associated with significantly higher ΔPV/VL (P=0.01) and a trend toward a higher ΔPI (P=0.06) than HT-only, but this association was markedly attenuated after adjustment to SRL conversion. HKT was associated with similar risk of death (adjusted hazard ratio [HR] 0.69, 95%CI: 0.28-1.71, P=0.43) and CAV-related events (adjusted HR 0.83, 95% CI: 0.30-2.31, P=0.72). Conversion to SRL was significantly associated with decreased risk of death and CAV-related events in the overall cohort. This association was not modified by the type of organ transplantation (Pinteraction=NS), and without a significant effect on estimated glomerular filtration rate (eGFR) or proteinuria. Conclusions HKT recipients compared to HT-only were less likely to be converted from CNI to SRL-based immunosuppression and had a greater CAV progression but without significant differences in all-cause mortality or CAV-related events. The clinical benefit and safety of conversion to SRL appeared similar in the HKT and isolated HT cohorts.

Abstract Background In light of the updated lowered threshold for diagnosing pulmonary hypertension (PH), the reversibility of precapillary PH with left ventricular assist device (LVAD) and the associated post heart transplantation (HT) outcomes remain unclear. Purpose and methods Using data from the United Network for Organ Sharing database, we aimed to investigate predictors of persistent precapillary PH in HT recipients bridged with LVAD, and examine the interrelated post-HT survival, using the updated pulmonary vascular resistance (PVR) cutoff of &gt;2 WU for precapillary PH. Results Among 2169 HT recipients bridged with LVAD, 1299 had PVR&gt;2 at baseline; 551 (42.4%) of whom normalized their PVR≤2 and 748 (57.6%) remained with elevated PVR&gt;2 after LVAD implantation. Female sex (adjusted odds ratio [aOR] 2.22, 95% confidence interval [CI]:1.61-3.07, p&lt;0.001) and inotropes-treatment at-listing (aOR 1.31, 95% CI: 1.03-1.66, p=0.028) were associated with persistently elevated PVR post LVAD. Conversely, longer duration of LVAD support (aOR 0.74, 95% CI: 0.65-.84, p&lt;0.001) and use of HeartMate 2 (aOR 0.74, CI: 0.59-0. 93, p=0.011) were protective against persistently elevated PVR post-LVAD. Persistently elevated PVR &gt;2 post-LVAD was associated with increased risk of death compared to those who normalized their PVR (adjusted hazard ratio [aHR] 1.26, 95% CI: 1.01-1.57, p=0.037). However, normalized PVR post-LVAD group had comparable survival to those with PVR≤2 at baseline (aHR 0.76, 95% CI: 0.57-1.02, p=0.07). Conclusions Many HT recipients bridged with LVAD remain with PVR&gt;2 post-LVAD implantation, which is associated with increased risk of death post-HT compared to patients with normalized PVR post-LVAD.

AbstractIntroductionData regarding ventricular tachycardia (VT) or premature ventricular complex (PVC) ablation in patients with aortic valve (AV) intervention (AVI) is limited. Catheter ablation (CA) can be challenging given perivalvular substrate in the setting of prosthetic valves. We sought to investigate the characteristics, safety, and outcomes of CA in patients with prior AVI and ventricular arrhythmias (VA).MethodsWe identified consecutive patients with prior AVI (replacement or repair) who underwent CA for VT or PVC between 2013 and 2018. We investigated the mechanism of arrhythmia, ablation approach, perioperative complications, and outcomes.ResultsWe included 34 patients (88% men, mean age 64 ± 10.4 years, left ventricular (LV) ejection fraction 35.2 ± 15.0%) with prior AVI who underwent CA (22 VT; 12 PVC). LV access was obtained through trans‐septal approach in all patients except one patient who had percutaneous transapical access. One patient had combined retrograde aortic and trans‐septal approach. Scar‐related reentry was the dominant mechanism of induced VTs. Two patients had bundle branch reentry VTs. In the VT group, substrate mapping demonstrated heterogeneous scar that involved the peri‐AV area in 95%. Despite that, the site of successful ablation included the periaortic region only in 6 (27%) patients. In the PVC group, signal abnormalities consistent with scar in the periaortic area were noted in 4 (33%) patients. In 8 (67%) patients, the successful site of ablation was unrelated to the periaortic area. No procedure‐related complications occurred. The survival and recurrence‐free survival rate at 1 year tended to be lower in VT group than in PVC group (p = .06 and p = .05, respectively) with a 1‐year recurrence‐free survival rate of 52.8% and 91.7%, respectively. No arrhythmia‐related death was documented on long‐term follow‐up.ConclusionCA of VAs can be performed safely and effectively in patients with prior AVI.

Left ventricular assist devices (LVADs) have been increasingly used in patients with advanced heart failure, either as a destination therapy or as a bridge to heart transplant. Continuous flow (CF) LVADs have revolutionized advanced heart failure treatment. However, significant vascular pathology and complications have been linked to their use. While the newer CF-LVAD generations have led to a reduction in some vascular complications such as stroke, no major improvement was noticed in the rate of other vascular complications such as gastrointestinal bleeding. This review attempts to provide a comprehensive summary of the effects of CF-LVAD on vasculature, including pathophysiology, clinical implications, and future directions.

We would like to thank the authors for their letter and interest in our manuscript. We appreciate their valuable comments. The authors have raised the following important points: 1. The heterogenicity of our cohort with mitral valve surgery (MVS) 2. Elucidating the characteristics and causes of ventricular arrhythmias (VA) in patients with primary versus secondary mitral disease as well as in those with ischemic versus non-ischemic heart disease 3. The paucity of cardiac magnetic resonance imaging (MRI) as a limitation of the study 4. The need for careful evaluation of patients prior to ablation since most arrhythmias did not originate from the perimitral area.

AbstractBackgroundData regarding ventricular tachycardia (VT) or premature ventricular complex (PVC) ablation following mitral valve surgery (MVS) is limited. Catheter ablation (CA) can be challenging given perivalvular substrate in the setting of mitral annuloplasty or prosthetic valves.ObjectiveTo investigate the characteristics, safety, and outcomes of radiofrequency CA in patients with prior MVS and ventricular arrhythmias (VA).MethodsWe identified consecutive patients with prior MVS who underwent CA for VT or PVC between January 2013 and December 2018. We investigated the mechanism of arrhythmia, ablation approach, peri‐operative complications, and outcomes.ResultsIn our cohort, 31 patients (77% men, mean age 62.3 ± 10.8 years, left ventricular ejection fraction 39.2 ± 13.9%) with prior MVS underwent CA (16 VT; 15 PVC). Access to the left ventricle was via transseptal approach in 17 patients, and a retrograde aortic approach was used in 13 patients. A combined transseptal and retrograde aortic approach was used in one patient, and a percutaneous epicardial approach was combined with trans‐septal approach in one patient. Heterogenous scar regions were present in 94% of VT patients and scar‐related reentry was the dominant mechanism of VT. Forty‐seven percent of PVC patients had abnormal substrate at the site targeted for ablation. Clinical VA substrates involved the peri‐mitral area in six patients with VT and five patients with PVC ablation. No procedure‐related complications were reported. The overall recurrence‐free rate at 1‐year was 72.2%; 67% in the VT group and 78% in the PVC group. No arrhythmia‐related death was documented on long‐term follow‐up.ConclusionCA of VAs can be performed safely and effectively in patients with MVS.