Dhanunjaya Lakkireddy

Left atrial volume predicts atrial fibrillation recurrence after radiofrequency ablation: a meta-analysis

Aims Left atrial (LA) diameter is a predictor of atrial fibrillation (AF) recurrence following radiofrequency catheter ablation (RFA). However, LA volume (LAV) is more accurate in assessing LA size. Studies evaluating LAV as a predictor of AF recurrence are contradictory; therefore, we performed a meta-analysis to assess whether LAV is an independent predictor of AF recurrence following RFA. Methods and results All studies reporting LAV/LAV index (LAVi) as a predictor of AF recurrence following RFA were included. For studies reporting mean LAV/ LAVi in patients with and without AF recurrence, standard difference in means (SDM) and standard errors were calculated, and combined using meta-analytical techniques. For studies reporting adjusted odds ratio (OR) for AF recurrence based on LAV/LAVi, log ORs were combined using generic inverse variance. Twenty one studies (3822 subjects) were included. Meta-analysis of 11 studies (1559 subjects) reporting LAV, showed that patients with AF recurrence had a higher mean LA volume compared to patients with no recurrence (SDM 0.801; CI 0.387-1.216). Data from 9 studies (1425 subjects) comparing LAVi showed that, patients with AF recurrence had a higher mean LAVi compared to patients with no recurrence (SDM-0.596; CI 0.305-0.888). Thirteen studies (2886 patients) reporting ORs for AF recurrence based on LAV/ LAVi, showed that LAV/LAVi was independently predictive of AF recurrence post-RFA (OR-1.032, CI- 1.012-1.052). Conclusions Patients with AF recurrence following RFA have a higher mean LAV/LAVi compared to patients with no recurrence. Large LAV/LAVi increases the odds of AF recurrence post RFA.

Left Atrial Appendage Closure for Stroke Prevention : Devices, Techniques, and Efficacy

Left atrial appendage closure can be performed either surgically or percutaneously. Surgical approaches include direct suture, excision and suture, stapling, and clipping. Percutaneous approaches include endocardial, epicardial, and hybrid endocardial-epicardial techniques. Left atrial appendage anatomy is highly variable and complex; therefore, preprocedural imaging is crucial to determine device selection and sizing, which contribute to procedural success and reduction of complications. Currently, the WATCHMAN is the only device that is approved for left atrial appendage closure in the United States.

Differential Benefits and Outcomes of Tirofiban vs Abciximab for Acute Coronary Syndromes in Current Clinical Practice

Little comparative data exist for glycoprotein IIb/IIIa inhibitors in acute coronary syndromes (ACS). Two hundred twenty-eight patients were studied: 114 received tirofiban (TI) and 114 received abciximab (AB) for either unstable angina (UA) or myocardial infarction (MI). All patients received aspirin, heparin, and ticlopidine or clopidogrel. Baseline characteristics were similar between the 2 groups for admitting diagnosis (UA vs MI), age, gender, ejection fraction, diabetes mellitus, prior coronary artery disease, prior myocardial infarction (MI), prior bypass surgery, hypertension, congestive heart failure, hyperlipidemia, MI type (Q vs non-Q), or location. Drug administration time (mean) was 13 hours (AB) and 24 hours (TI). All AB was administered in the catheterization laboratory as compared to TI (34% in laboratory and 66% before laboratory). More AB patients received angioplasty or stent (92% vs 80%, p = 0.008) while more TI patients had CABG (10% vs 3%, p = 0.027). In-hospital complications including death, MI, urgent revascularization, cerebrovascular accidents or transient ischemic attacks, and access site bleeding were similar (p = NS). Multivariate predictors of events (odds ratios) were prior coronary artery bypass graft (2.3), diabetes (1.7), and prior percutaneous translu minal coronary angioplasty (1.7), but not the agent used. Over a mean follow-up of 13 months, the individual endpoints of death, MI, revascularization, or hospitalization were similar for both groups. The AB patients had improved freedom from revascularization (100% vs 81%, p=0.015) in an emergent setting and TI patients had improved freedom from revascularization (93% vs 77%, p= 0.038) with elective procedures. Tirofiban and abciximab appear effective and safe when used for ACS when recommended dosing and precautions are followed. Major adverse outcomes are rare and bleeding complications uncommon.

Left Atrial Appendage Closure for Stroke Prevention is Safe and Effective in Selected Patients with Atrial Fibrillation

The left atrial appendage (LAA) is implicated as a source of thrombus in the majority of patients with atrial fibrillation (AF) and embolic stroke. Therapeutic anticoagulation (AC) is the mainstay of treatment for stroke prophylaxis in AF. Despite adherence to AC, a significant number of patients are still subtherapeutic. In addition to this, several patients are ineligible for AC because of various reasons, including but not limited to high bleeding risk, ongoing bleeding, and non-compliance. These challenges associated with AC led to efforts looking at mechanical isolation of the LAA. Various endocardial and epicardial devices have been tried for mechanical isolation of the LAA, with variable success. The WATCHMANt (Boston Scientific, Maple Grove, MN) is the first endocardial device that received FDA approval as an alternative for warfarin for stroke prophylaxis in AF. The WATCHMANt (Boston Scientific) is not approved for AC-ineligible patients. The LARIAT (SentreHEART, Inc., Redwood City, CA) is an epicardially deployed device that has been proposed for AC-ineligible patients. Although not FDA approved, its safety and efficacy had been established in large prospective registries. The current review examines the current literature on AC and LAA exclusion devices in a comparative fashion. The protean effects of LARIAT (SentreHEART, Inc.) on rhythm and neurohormonal control are also reviewed. We conclude that LAA exclusion devices are an excellent alternative to AC for stroke prophylaxis in AC-eligible (WATCHMANt, Boston Scientific) and ineligible patients (LARIAT, SentreHEART).

Age-Dependent Impact of Fluoroscopic Radiation on the Gender of Off-Spring: An International Survey of Cardiologists.

Background: Fluoroscopic radiation has been implicated in reducing the sex ratio (M:F) by potentially damaging the Y chromosome. We examined the effects of exposure to fluoroscopic radiation on gender of offspring of cardiologists across the world. Methods: An internet based survey was e-mailed worldwide to 8000 physicians who practice invasive electrophysiology and/or interventional cardiology. Survey questions included age, race, sub-specialty, hours of exposure to radiation, number of children, gender of off-spring, miscarriages and mutations and exposure to radiation prior to conception of each child. Logistic regression analyses were performed on years of exposure and gender of offspring born post radiation exposure. Results: Responses of 377 cardiologists (84% male and 16% female) were reviewed. With a total of 398 males and 402 females born to 377 cardiologists, although reduced, the overall sex ratio (0.99) was not significantly different from that observed in the general population (1.05). Univariate logistic regression analysis identified higher male births with increasing hours of radiation exposure (OR 1.034, CI 1.003-1.067 p=0.03) and increasing paternal age (OR 1.05, CI 1.01-1.08, p=0.002). Subgroup analysis of children of male cardiologists revealed higher incidence of male births with increasing age and radiation exposure and multivariate analysis only identified paternal age as predictor of higher incidence of male births (OR 1.05, CI 1.01-1.089, p=0.0027). Conclusion: Exposure to ionizing radiation leads to a decrease in the sex ratio (M/F) in younger male cardiologists, while this effect is reversed with greater number of male births in older male cardiologists.