Rattanawong, Pattara

Introduction: Syncope was reported to be associated with sudden cardiac death in heart failure patients regardless of the etiology of syncope. We attempted to use unsupervised machine learning to identify the prognostically distinct phenotypes in a large population of heart failure patients presenting with syncope. Hypothesis: Unsupervised machine learning can identify prognostically distinct phenotypes in a large population of heart failure patients presenting with syncope. Methods: Patients with a diagnosis of systolic or diastolic heart failure and syncope at Mayo Clinic sites were identified for baseline and follow-up data. Variables with ≥ 20% missing data were excluded; a total of 57 variables were used for k-means clustering analysis. Patients were grouped according to 4 distinct k-means determined clusters for statistical analysis. Results: A total of 3,557 patients with proper follow-up and echocardiography data were included in the final analysis. The median follow-up duration was 36.3 months, and 2908 (81.7%) patients died. Cluster 2 (n= 680) was identified as the cluster with the highest mortality (92%), which contained patients with high proportions of cardiovascular comorbidities, especially chronic kidney disease. The Kaplan-Meier survival curves are shown in Figure 1. In multivariate Cox regression analysis, the presence of CKD independently predicts mortality (HR 1.62, 95%CI 1.50-1.76, p <0.0001) after adjusting for age and sex. Conclusions: Unsupervised machine learning identified patients with CKD, CAD and DM are high-risk phenotypes in heart failure patients with syncope, and can be used to guide future studies in this highly heterogeneous, unexplored population.

Introduction: Catheter ablation of the arrhythmogenic substrate reduces the recurrence of ventricular tachycardia (VT) in patients with ischemic cardiomyopathy and implantable cardioverter-defibrillator (ICD). However, the all-cause mortality benefit in this population is unclear. Hypothesis: Prophylactic ablation of the arrhythmogenic substrate decreases all-cause mortality and prevents the recurrence of VT/ventricular fibrillation (VF) in patients with ischemic cardiomyopathy. Methods: We searched the MEDLINE and EMBASE databases from inception through May 2021. We included randomized controlled trials that compared all-cause mortality and ventricular arrhythmia recurrence in patients with ischemic cardiomyopathy who underwent ICD implantation with and without prophylactic ablation. The data from each study was combined using a fixed effects model to calculate the hazard ratio and 95% confidence interval (CI). Results: Four randomized controlled trials during 2007-2020 involving 505 patients (249 patients with and 256 patients without prophylactic VT ablation) were included in our meta-analysis. Compared with control, prophylactic VT ablation did not decrease the all-cause mortality (pooled hazard ratio = 0.94, 95% CI 0.54-1.63, p = 0.818, I2 = 5.8%). However, prophylactic VT ablation significantly decreased appropriate ICD therapy (pooled hazard ratio = 0.58, 95% CI 0.41-0.82, p = 0.002, I 2 = 26.1%) and VT/VF recurrence (pooled hazard ratio = 0.70, 95% CI 0.52-0.93, p = 0.015, I 2 = 0.0%). Conclusions: Prophylactic VT ablation in patients with ischemic cardiomyopathy did not decrease all-cause mortality; however, it did lead to decreased appropriate ICD therapy and VT/VF recurrence.

AbstractBackgroundPosterior wall isolation (PWI) is an emerging approach in atrial fibrillation (AF) ablation, yet its efficacy remains controversial. This is the first meta‐analysis of randomized controlled trials (RCT) to evaluate the efficacy of PWI in AF ablation.ObjectiveTo assess the efficacy of PWI in reducing atrial arrhythmia recurrence following initial AF ablation at long‐term follow‐ups when compared to conventional methods.MethodsWe conducted a literature search from inception through September 2021 in EMBASE and MEDLINE databases. We included RCTs that compared outcomes in PWI and conventional approaches of AF ablation. Data from each study were combined using the random‐effects, generic inverse variance method of DerSimonian and Laird to calculate odds ratio (OR), and 95% confidence interval (CI).ResultsEight RCT from 2009 to 2020, including 1024 AF patients, were included. PWI did not decrease overall atrial arrhythmias recurrence (RR 0.96, 95% CI:0.88–1.05, I2 = 31.6%, p‐value 0.393). However, the pooled analysis showed a significant decrease in AF recurrence in PWI compared to controlled approaches (RR 0.88, 95% CI:0.81–0.96, I2 = 48.2%, p‐value .004). In the subgroup analysis, PWI significantly decreased AF recurrence in the studies that included only persistent AF (RR = 0.89, 95% CI:0.80–0.98, I2 = 65.2%, p‐value .014). PWI significantly decreased AF recurrence when compared to PVI with roof line (RR 0.84, 95% CI 0.74–0.95, I2 0.00%, p‐value .008).ConclusionOur study suggests that adding PWI significantly decreased AF recurrence in patients with persistent AF compared to controlled approaches. It highlights the importance of considering PWI during the initial procedure in this patient population.

AbstractBackgroundRadiofrequency catheter ablation for cardiac arrhythmias has traditionally been guided by fluoroscopy. Fluoroscopy exposes the patient, operator, and staff to ionizing radiation which has no safe dose void of stochastic and deterministic biologic risks. Zero fluoroscopy (ZF) approaches for catheter ablation have been advocated to eliminate these risks. We conducted a meta‐analysis comparing acute procedure success, recurrence‐free survival, complications, and procedure times between the approaches.MethodsWe conducted a literature search from inception through December 2020 in the databases of EMBASE and MEDLINE. We included randomized controlled trials and cohorts that compared the outcomes of interest in ZF and conventional/low fluoroscopy (CF/LF) approaches. The outcomes sought were acute procedure success, recurrence‐free survival, complications, and procedure times. Effect estimates were combined, using the random‐effects, generic inverse variance method of DerSimonian and Laird.ResultsSixteen studies from 2013 to 2020, including 6052 patients (2219 ZF, 3833 CF/LF) were included. There were no significant differences in acute procedure success rate (odds ratio [OR]: 1.10, 95% confidence interval [CI]: 0.75–1.59), recurrence‐free survival (OR: 1.08, 95% CI: 0.78–1.49), periprocedural complication rate (OR: 0.72, 95% CI: 0.45–1.16), or total procedure time (weighted mean difference 2.32 min, 95% CI: −2.85–7.50) between ZF and CF/LF approaches, respectively. Overall, only 1.26% of patients crossed over from ZF to CF/LF arm.ConclusionsPeriprocedural and postprocedural outcomes with a ZF approach compared favorably with traditional fluoroscopic guidance without increasing procedural times. As comfort with ZF grows, coupled with evolving mapping technologies, this method has potential to become the standard approach for catheter ablation.

Background Brugada syndrome is an inherited cardiac channelopathy associated with major arrhythmic events (MAEs). The presence of a positive family history of sudden cardiac death (SCD) as a risk predictor of MAE remains controversial. We aimed to examine the association between family history of SCD and MAEs stratified by age of SCD with a systematic review and meta‐analysis. Methods and Results We searched the databases of MEDLINE and EMBASE from January 1992 to January 2020. Data from each study were combined using the random‐effects model. Fitted metaregression was performed to evaluate the association between the age of SCD in families and the risk of MAE. Twenty‐two studies from 2004 to 2019 were included in this meta‐analysis involving 3386 patients with Brugada syndrome. The overall family history of SCD was not associated with increased risk of MAE in Brugada syndrome (pooled odds ratio [OR], 1.11; 95% CI, 0.82–1.51; P =0.489, I 2 =45.0%). However, a history of SCD in family members of age younger than 40 years of age did increase the risk of MAE by ≈2‐fold (pooled OR, 2.03; 95% CI, 1.11–3.73; P =0.022, I 2 =0.0%). When stratified by the age of cut point at 50, 45, 40, and 35 years old, a history of SCD in younger family member was significantly associated with a higher risk of MAE (pooled OR, 0.49, 1.30, 1.51, and 2.97, respectively; P =0.046). Conclusions A history of SCD among family members of age younger than 40 years was associated with a higher risk of MAE.

Introduction: Drug challenge testing is performed to unmask Type-1 Brugada pattern. The safety and prevalence of its complications during the test are unclear. We aimed to assess the relation of complications in patients with positive and negative results by a systematic review and meta-analysis. Hypothesis: The prevalence of arrhythmic complications is higher in patients with positive drug challenge testing. Methods: We comprehensively searched the databases of MEDLINE and EMBASE from inception to June 2020. Included studies were cohort studies that reported ventricular arrhythmia that required interventions (VAI) (sustained ventricular tachycardia [VT], polymorphic VT, ventricular fibrillation, appropriate implantable cardioverter defibrillator [ICD] shock, or sudden cardiac arrest) and ventricular arrhythmias that did not required interventions (VANI) (premature ventricular complexes and non-sustained VT) during drug challenge testing. Data were combined using the random-effects model. Results: Thirteen studies involving 2,688 patients (62.7% positive) were included. The overall prevalence of VAI and VANI were 3.7% (95% confidence interval [CI]: 1.8-5.7) and 0.5% (95% CI: 0.1-0.9), respectively. VAI were more common in positive when compared to negative test result patients (1.5% [95% CI: 0.6-2.4] and 0%, respectively) but the prevalence of VANI were similar (2.7% [95% CI: 0.8-4.6] and 2.6% [95% CI: 0.8-4.6], respectively). VAI in positive result patients were more common with flecainide followed by pilsicainide and ajmaline (2.4% [95% CI: -4.3 to 9.2], 2.2% [95% CI: 0.5-4.0], and 1.5% [95% CI: 0.6 to 2.4], respectively). Most of patients with VAI during drug challenge testing underwent ICD implantation (94%). VAI during drug challenge testing in positive result patients carries an increased risk of VAI during 8.6 ± 4.9 years follow-up (odds ratio 3.73, 95% CI: 1.77-7.86, p=0.001). Conclusions: VAI were more common in patients with positive drug challenge testing, more often occurring with positive flecainide challenge, and carries an increased risk of VAI over long-term follow-up in patients with positive drug challenge testing.

Background: Although high power, shorter duration (HPSD) ablation and low power, longer duration (LPLD) ablation strategies for atrial fibrillation (AF) are frequently advocated to enhance safety and efficacy, there exists a need for comparative data from large populations. We performed a meta-analysis to compare arrhythmia-free survival, procedure time and complications rates between the two strategies. Methods: We searched the databases of MEDLINE and EMBASE from inception to April 2020. Included studies were case-control studies, cohort studies, or randomized controlled trials that compared patients undergoing HPSD and LPLD strategies for AF ablation and reported either of the following outcomes: freedom from atrial tachyarrhythmia (AT) including AF and atrial flutter, procedure time, or periprocedural complications. Data from each study were combined using the random-effects model to calculate odds ratio (OR) and weighted mean difference (WMD) with 95% confidence interval (CI). Results: Ten studies from 2006 to 2020 involving 2,189 patients were included (1,350 patients underwent HPSD strategy and 839 patients underwent LPLD strategy). Both HPSD and LPLD strategies resulted in a similar freedom from AT at 12-month follow-up (OR=1.36, 95% CI:0.91-2.04, p=0.13, Figure 1A). HPSD strategy did result in a significant reduction in total procedure time (WMD=47.34, 95% CI:29.47-65.21, p<0.001, Figure 1B) compared to LPSD. HPSD wasn’t associated with reduction in esophageal ulcer/arterioesophageal fistula (OR=0.35, 95%CI=0.12-1.06, p=0.06) or pericardial effusion/cardiac tamponade (OR=0.96, 95%CI: 0.24-3.79, p=0.95) Conclusions: In this large meta-analysis both LPLD and HPSD are equally effective and safe. Although HPSD is often advocated to reduce esophageal injury, risk was similar between approaches. However, HPSD strategy significantly lowers procedure times.

Background. There is no consensus guidance on when to reinitiate Pneumocystis jirovecii pneumonia (PJP) prophylaxis in solid organ transplant (SOT) recipients at increased risk. The 2019 American Society of Transplantation Infectious Diseases Community of Practice (AST IDCOP) guidelines suggested to continue or reinstitute PJP prophylaxis in those receiving intensified immunosuppression for graft rejection, cytomegalovirus (CMV) infection, higher dose of corticosteroids, or prolonged neutropenia. Methods. A literature search was conducted evaluating all literature from existence through April 22, 2020, using MEDLINE and EMBASE. (The International Prospective Register of Systematic Reviews registration number: CRD42019134204). Results. A total of 30 studies with 413 276 SOT recipients were included. The following factors were associated with PJP development: acute rejection (pooled odds ratio [pOR], 2.35; 95% confidence interval [CI], 1.69-3.26); study heterogeneity index [I2] = 23.4%), CMV-related illnesses (pOR, 3.14; 95% CI, 2.30-4.29; I2 = 48%), absolute lymphocyte count <500 cells/mm3 (pOR, 6.29; 95% CI, 3.56-11.13; I2 = 0%), BK polyomavirus-related diseases (pOR, 2.59; 95% CI, 1.22-5.49; I2 = 0%), HLA mismatch ≥3 (pOR, 1.83; 95% CI, 1.06-3.17; I2 = 0%), rituximab use (pOR, 3.03; 95% CI, 1.82-5.04; I2 = 0%), and polyclonal antibodies use for rejection (pOR, 3.92; 95% CI, 1.87-8.19; I2 = 0%). On the other hand, sex, CMV mismatch, interleukin-2 inhibitors, corticosteroids for rejection, and plasmapheresis were not associated with developing PJP. Conclusions. PJP prophylaxis should be considered in SOT recipients with lymphopenia, BK polyomavirus-related infections, and rituximab exposure in addition to the previously mentioned risk factors in the American Society of Transplantation Infectious Diseases Community of Practice guidelines.

Gastrointestinal bleeding (GIB) especially from arteriovenous malformations (AVM) remains one of the devastating complications following continuous-flow left ventricular device (CF-LVAD) implantation. Blockade of angiotensin II pathway using angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB) was reported to mitigate the risk of GIB and AVM-related GIB by suppressing angiogenesis. We performed a systematic review and meta-analysis to evaluate the association between ACEI/ARB treatment and GIB in CF-LVAD population. Comprehensive literature search was performed through December 2019. We included studies reporting risk of GIB and/or AVM-related GIB events in LVAD patients who received ACEI/ARB with those who did not. Data from each study were combined using the random-effects to calculate odd ratios and 95% confidence intervals. Three retrospective cohort studies were included in this meta-analysis involving 619 LVADs patients (467 patients receiving ACEI/ARB). The use of ACEI/ARB was statistically associated with decreased incidence of overall GIB (pooled OR 0.35, 95% CI 0.22–0.56, I 2 = 0.0%, p < 0.001). There was a non-significant trend toward lower risk for AVM-related GIB in patients who received ACEI/ARB (pooled OR 0.46, 95% CI 0.19–1.07, I 2 = 51%, p = 0.07). Larger studies with specific definitions of ACEI/ARB use and GIB are warranted to accurately determine the potential non-hemodynamic benefits of ACEI/ARB in CF-LVAD patients.