Oral mexiletine for ventricular tachyarrhythmias treatment in implantable cardioverter-defibrillator patients: a systematic review of the literature.

INTRODUCTION: To evaluate the clinical outcomes of oral mexiletine (oMXT) to treat ventricular tachyarrhythmias (VTAs) in the era of implantable cardioverter-defibrillator (ICD) technology. EVIDENCE ACQUISITION: A systematic search was conducted using PubMed, Embase and Cochrane databases following the PRISMA guidelines to collect literature data reporting oMXT efficacy and safety outcomes in treating VTAs in ICD recipients. EVIDENCE SYNTHESIS: Final analysis included four studies accounting for a total of 91 patients with recurrent VTAs treated with oMXT. Amiodarone therapy was initially attempted in most patients (91.2%), while catheter ablation was performed in one-third of patients. VTA recurrences were observed in 55/91 patients (60.4%) during oMXT treatment compared to 91/91 (100%) before treatment (P<0.001). Appropriate therapies occurred in 55/88 ICD patients (62.5%) during oMXT treatment compared to 80/88 (90.9%) before treatment (P<0.001). After oMXT introduction, there was a significant reduction of the individual burden of VTA episodes and appropriate ICD therapies per patient, showing Hedges'g values of -1.103 (P=0.002) and -1.474 (P=0.008), respectively. Safety analysis showed a sample-weighted overall side-effect rate of 30%, while 21% of patients required drug reduction or discontinuation. Aggregated meta-regression analysis of the included studies and remote literature revealed a linear correlation between oMXT dosage and the overall side effects rate (r2 = 0.48; P=0.014). CONCLUSIONS: Oral mexiletine provides an adjunctive treatment to manage VTAs and reduces appropriate therapies in ICD patients with moderate efficacy and acceptable safety profiles. These observations await confirmation through randomised clinical trials.

Bacterial footprints in aspirate of infarct-related artery in ST-elevation myocardial infarction patients underwent primary percutaneous coronary intervention.

BACKGROUND: Bacterial infections can trigger acute coronary syndromes. This study aimed to examine bacterial footprints in the aspirate of infarct-related artery. PATIENTS AND METHODS: We studied 140 patients with ST-elevation myocardial infarction who underwent a primary coronary intervention using thrombus aspiration catheters. The aspirate was sent for bacteriological and pathological examinations and immunoassay for pneumolysin toxin. RESULTS: Bacterial culture showed different bacteria in 14 samples. Leukocyte infiltrate was detected in all pathologically examined samples. Pneumolysin toxin was detected in only two samples. Patients with bacteria had similar baseline data as those without, except for the median age [46 (44-50) vs. 55 (47-62) years, P = 0.001, respectively], and white blood cells (WBCs) (16670 vs. 7550 cells/µl, P < 0.0001, respectively). In hospital-major clinical events (death, stroke, reinfarction, lethal arrhythmia, and heart failure) were not significantly different between the 2 groups with and without bacteria [4 (28.6%) vs. 20 (18.6%) events, respectively, odds ratio (OR) 1.8 (95% CL: 06-6.3), P = 0.5]. Patients with bacteria, heavy infiltration, and pneumolysin had insignificant higher events compared with those without [10/35 (28.6%) vs. 16/105 (15.2%) events, OR 2.2 (95% CL: 0.92-5.43), P = 0.13]. However, the difference was not significant. By multivariate analysis, bacteria, leukocyte infiltration, and pneumolysin were not predictors for in-hospital clinical events. Higher WBCs and younger age were significant predictors of bacterial footprints (P < 0.0001 and P = 0.04, respectively). CONCLUSION: Bacterial footprints existed in the aspirate of infarct-related artery of ST-elevation myocardial infarction patients. Predictors were higher WBCs and younger age. Bacterial markers were not predictors for in-hospital clinical events. The presence of bacterial footprints supports the infectious hypothesis of atherosclerosis.