Mikhael F. El-Chami

New-Onset Atrial Fibrillation Predicts Long-Term Mortality After Coronary Artery Bypass Graft

OBJECTIVES We sought to investigate the association between new-onset atrial fibrillation after coronary artery bypass graft (CABG) (post-operative atrial fibrillation [POAF]) and long-term mortality in patients with no history of atrial fibrillation. BACKGROUND POAF predicts longer hospital stay and greater post-operative mortality. METHODS A total of 16,169 consecutive patients with no history of AF who underwent isolated CABG at our institution between January 1, 1996, and December 31, 2007, were included in the study. All-cause mortality data were obtained from Social Security Administration death records. A multivariable Cox proportional hazards regression model was constructed to determine the independent impact of new-onset POAF on long-term survival after adjusting for several covariates. The covariates included age, sex, race, pre-operative risk factors (ejection fraction, New York Heart Association functional class, history of myocardial infarction, index myocardial infarction, stroke, chronic obstructive pulmonary disease, peripheral arterial disease, smoking, diabetes, renal failure, hypertension, dyslipidemia, creatinine level, dialysis, redo surgery, elective versus emergent CABG, any valvular disorder) and post-operative adverse events (stroke, myocardial infarction, acute respiratory distress syndrome, and renal failure), and discharge cardiac medications known to affect survival in patients with coronary disease. RESULTS New-onset AF occurred in 2,985 (18.5%) patients undergoing CABG. POAF independently predicted long-term mortality (hazard ratio: 1.21; 95% confidence interval: 1.12 to 1.32) during a mean follow-up of 6 years (range 0 to 12.5 years). This association remained true after excluding from the analysis those patients who died in-hospital after surgery (hazard ratio: 1.21; 95% confidence interval: 1.11 to 1.32). Patients with POAF discharged on warfarin experienced reduced mortality during follow-up. CONCLUSIONS In this large cohort of patients, POAF predicted long-term mortality. Warfarin anticoagulation may improve survival in POAF.

Predictors and Clinical Outcomes of Permanent Pacemaker Implantation After Transcatheter Aortic Valve Replacement: The PARTNER (Placement of AoRtic TraNscathetER Valves) Trial and Registry

OBJECTIVES The purpose of this study was to identify predictors and clinical implications of permanent pacemaker (PPM) implantation after transcatheter aortic valve replacement (TAVR). BACKGROUND Cardiac conduction disturbances requiring PPM are a frequent complication of TAVR. However, limited data is available regarding this complication after TAVR with a balloon-expandable valve. METHODS The study included patients without prior pacemaker who underwent TAVR in the PARTNER (Placement of AoRtic TraNscathetER Valves) trial and registry and investigated predictors and clinical effect of new PPM. RESULTS Of 2,559 TAVR patients, 586 were excluded due to pre-existing PPM. A new PPM was required in 173 of the remaining 1,973 patients (8.8%). By multivariable analysis, predictors of PPM included right bundle branch block (odds ratio [OR]: 7.03, 95% confidence interval [CI]: 4.92 to 10.06, p < 0.001), prosthesis diameter/left ventricular (LV) outflow tract diameter (for each 0.1 increment, OR: 1.29, 95% CI: 1.10 to 1.51, p = 0.002), LV end-diastolic diameter (for each 1 cm, OR: 0.68, 95% CI: 0.53 to 0.87, p = 0.003), and treatment in continued access registry (OR: 1.77, 95% CI: 1.08 to 2.92, p = 0.025). Patients requiring PPM had a longer mean duration of post-procedure hospitalization (7.3 ± 2.7 days vs. 6.2 ± 2.8 days, p = 0.001). At 1 year, new PPM was associated with significantly higher repeat hospitalization (23.9% vs. 18.2%, p = 0.05) and mortality or repeat hospitalization (42.0% vs. 32.6%, p = 0.007). There was no difference between groups in LV ejection fraction at 1 year. CONCLUSIONS PPM was required in 8.8% of patients without prior PPM who underwent TAVR with a balloon-expandable valve in the PARTNER trial and registry. In addition to pre-existing right bundle branch block, the prosthesis to LV outflow tract diameter ratio and the LV end-diastolic diameter were identified as novel predictors of PPM after TAVR. New PPM was associated with a longer duration of hospitalization and higher rates of repeat hospitalization and mortality or repeat hospitalization at 1 year. (THE PARTNER TRIAL: Placement of AoRtic TraNscathetER Valves Trial; NCT00530894).

Cardiovascular Effects of Exposure to Cigarette Smoke and Electronic Cigarettes : Clinical Perspectives From the Prevention of Cardiovascular Disease Section Leadership Council and Early Career Councils of the American College of Cardiology

Cardiovascular morbidity and mortality as a result of inhaled tobacco products continues to be a global healthcare crisis, particularly in low- and middle-income nations lacking the infrastructure to develop and implement effective public health policies limiting tobacco use. Following initiation of public awareness campaigns 50 years ago in the United States, considerable success has been achieved in reducing the prevalence of cigarette smoking and exposure to secondhand smoke. However, there has been a slowing of cessation rates in the United States during recent years, possibly caused by high residual addiction or fatigue from cessation messaging. Furthermore, tobacco products have continued to evolve faster than the scientific understanding of their biological effects. This review considers selected updates on the genetics and epigenetics of smoking behavior and associated cardiovascular risk, mechanisms of atherogenesis and thrombosis, clinical effects of smoking and benefits of cessation, and potential impact of electronic cigarettes on cardiovascular health.

The Subcutaneous Defibrillator: A Review of the Literature

The recently commercially available subcutaneous implantable cardioverter-defibrillator (S-ICD) uses a completely subcutaneous electrode configuration to treat potentially lethal ventricular tachyarrhythmia. Clinical trials have proven its effectiveness in detecting and treating ventricular fibrillation and tachycardia. The S-ICD offers the advantage of eliminating the need for intravenous and intracardiac leads and their associated risks and shortcomings. However, its major disadvantage is its inability to provide bradycardia rate support and antitachycardia pacing to terminate ventricular tachycardia. This paper discusses the S-ICD clinical trials and advantages and disadvantages of this novel technology to help the physician identify its role and select candidate patients who will benefit from this device.

Clinical outcomes three years after PLAATO implantation.

Background: The percutaneous left atrial appendage transcatheter occlusion system (PLAATO) is an alternative to coumadin in patients with atrial fibrillation (AF) and contraindications to anticoagulation. It appears to be protective against stroke in intermediate follow‐up studies. Hypothesis: The PLAATO system is protective against stroke and is safe in long‐term follow‐up. Methods: Eleven patients (age 72 ± 9 years) enrolled in the PLAATO feasibility and safety trial at our institution were followed (36 ± 1.4) months. All patients had contraindications to anticoagulation and had at least one risk factor for stroke. The predicted stroke risk for this cohort was 8.6% per year as calculated using the CHADS2 score (A validated scoring system assigning 1 point for CHF, hypertension, diabetes, and age >75 years, and 2 points for history of stroke). The primary end‐point was the incidence of stroke, and secondary end points were complications related to PLAATO device and systemic embolic events. Results: There was one stroke during follow‐up; the stroke risk in our population was 3% per year. Interestingly, the observed stroke risk in these patients after occluding the left atrial appendage is comparable to what would have been observed with warfarin. No systemic embolic events were noted in our cohort and no long term complications related to PLAATO were seen. Conclusion: The PLAATO device decreases the risk of stroke in a high‐risk cohort of AF patients. Furthermore, the safety of this device is confirmed during this long‐term follow‐up study. A larger trial is needed to validate these findings.

Subcutaneous implantable cardioverter-defibrillator Post-Approval Study: Clinical characteristics and perioperative results

BACKGROUND The subcutaneous implantable cardioverter-defibrillator (S-ICD) was developed to reduce short- and long-term complications associated with transvenous ICD leads. Early multicenter studies included younger patients with less left ventricular systolic dysfunction and fewer comorbidities than cohorts with traditional ICD. OBJECTIVE The purpose of this study was to characterize patient selection and the acute performance of the S-ICD in a contemporary real-world setting. METHODS The S-ICD Post-Approval Study is a prospective registry involving 86 US centers. Patients were enrolled if they met criteria for S-ICD implantation, passed an electrocardiogram screening test, and had a life expectancy of >1 year. Analyses of descriptive statistics, Kaplan-Meier time to event, and multivariate logistic regression were performed. RESULTS The study includes 1637 patients who underwent S-ICD implantation. The cohort included 68.6% (1123/1637) male patients, and 13.4% (220/1636) were receiving dialysis for end-stage renal disease. The mean age was 52 ± 15 years, with a mean left ventricular ejection fraction of 32.0% ± 14.6%. Electrocardiogram screening was successful for at least 1, 2, or 3 vectors in 100%, 93.8%, and 51.4% of patients, respectively. Medical imaging (65.1%, 1065/1636) and general anesthesia (64.1%, 1048/16) were used in a majority of patients, and 52.2% (855/1637) were implanted with the 2-incision technique. Induced ventricular tachycardia/ventricular tachycardia was successfully converted in 98.7% (1394/1412) of patients. The 30-day complication-free rate was 96.2%. Predictors of complications included diabetes, younger age, and higher body mass index. CONCLUSION Contemporary US patients with S-ICD have more comorbidities than do previous cohorts with S-ICD, but they are younger with more end-stage renal disease than do patients with transvenous ICD. Implantation success is high, and short-term complication rates are acceptable.

Performance of a novel left ventricular lead with short bipolar spacing for cardiac resynchronization therapy: primary results of the Attain Performa quadripolar left ventricular lead study.

BACKGROUND The Medtronic Attain Performa quadripolar leads provide 16 pacing vectors with steroid on every electrode. This includes a short bipolar configuration between the middle 2 electrodes. OBJECTIVE A prospective clinical study was conducted to investigate the safety and effectiveness of these new leads in 27 countries. METHODS Cardiac resynchronization therapy with defibrillator candidates were enrolled (mean age 68 years; 71% men). All implanted subjects were followed at 1, 3, and 6 months postimplant. Pacing capture threshold (PCT) values were measured at each visit. Adverse events were reported upon occurrence. RESULTS Of 1124 subjects in whom a left ventricular (LV) lead was attempted, 1097 (97.6%) were successfully implanted with an Attain Performa lead. Thirty-six LV lead-related complications were reported (the 6-month LV lead-related complication-free survival rate was 96.9%). Phrenic nerve stimulation (PNS) occurred in 81 subjects (7.2%), with only 3 (0.3%) requiring surgical intervention. At 6 months, the mean PCT at the programmed vector was (1.1 ± 0.8) V and 94.4% of subjects had a PCT of ≤2.5 V. All 16 programming polarities were used in at least 1 patient, and short bipolar configurations were used in 17% of subjects. CONCLUSION This large multicenter study demonstrated a high success rate for the implantation of Attain Performa quadripolar LV leads with a low complication rate. The PCT was low and stable over time. A low rate of postimplantation PNS was observed, and cases of PNS were readily resolved with reprogramming. Nonstandard vectors were often used for LV pacing.

Outcome of Subcutaneous Implantable Cardioverter Defibrillator Implantation in Patients with End‐Stage Renal Disease on Dialysis

Although the subcutaneous ICD (S‐ICD®) is an attractive alternative in patients with end‐stage renal disease (ESRD), data on S‐ICD outcomes in dialysis patients are lacking.

QRS Duration Is Associated With Atrial Fibrillation in Patients With Left Ventricular Dysfunction

QRSduration (QRSd) is associated with higher mortality and morbidity in patients with left ventricular (LV) dysfunction. The association between QRSd and atrial fibrillation (AF) has not been studied in this patient population.

Implantable Cardioverter-Defibrillators at End of Battery Life: Opportunities for Risk (Re)-Stratification in ICD Recipients.

Although implantable cardioverter-defibrillators (ICDs) are frequently viewed as a lifelong commitment in that patients are routinely scheduled for generator exchange (GE) at end of battery life, several considerations should prompt a reevaluation of risks and benefits before GE. Compared with initial ICD implant, patients receiving replacement devices are older, and have more comorbidities and shorter life expectancy, all of which may limit the benefit of ICD therapy following GE. Additionally, GE is associated with significant complications, including infection, which may increase the risk of mortality. In this paper, we review recent data regarding opportunities for risk stratification before GE, with a particular focus on those with improved left ventricular function and those who have not experienced ICD therapies during the first battery life. We also provide a broader perspective on ICD therapy, focusing on how decisions regarding GE may affect goals of care at the end of life.