Safety and Effectiveness of a Next-Generation Contact Force Catheter: Results of the TactiSense Trial.

OBJECTIVES: The objective of this clinical trial was to evaluate the safety and effectiveness of the TactiCath Contact Force Ablation Catheter, Sensor Enabled (TactiCath SE) (Abbott, Abbott Park, Illinois) for the treatment of drug-refractory, symptomatic paroxysmal atrial fibrillation (PAF). BACKGROUND: Catheter ablation of atrial fibrillation (AF) is an established therapy for the treatment of PAF. Ablation technology is evolving with the primary goals of improving efficacy and safety of the procedure. METHODS: This was a multicenter single-arm trial evaluating a novel ablation catheter for the treatment of PAF. A total of 156 subjects were enrolled at 19 sites in the United States, Europe, and Australia. The primary safety endpoint was the rate of device- or procedure-related serious adverse events occurring within 7 days. The primary effectiveness endpoint was acute success defined as pulmonary vein isolation at 30 min after ablation. Two descriptive endpoints were prospectively captured: 1) 1-year freedom from recurrence of symptomatic AF, atrial flutter (AFL), and atrial tachycardia (AT) lasting ≥30 s without a new or increased dose of Class I/III antiarrhythmic drugs; and 2) 1-year drug-free success defined by the absence of any recurrent AF/AFL/AT lasting ≥30 s without using Class I/III antiarrhythmic drugs. RESULTS: Primary safety events occurred in 4.7% of patients (95% confidence interval [CI]: 2.23% to 8.64%), and the procedure was acutely successful in 98.0% of patients (95% CI: 94.95% to 99.46%). According to Kaplan-Meier estimates at 1 year, 82.2% (95% CI: 74.7% to 87.6%) were free from symptomatic recurrence, and 1-year drug-free success was 68.2% (95% CI: 59.9% to 75.1%). CONCLUSIONS: The TactiCath™ Contact Force Ablation Catheter, Sensor Enabled™ is safe and effective for the treatment of paroxysmal AF.

Sleeping altitude and sudden cardiac death.

BACKGROUND: Mountain activities characterized by strenuous exercise in a hypoxic setting place unique demands on the body. The mortality rate associated with mountain activities is high, with sudden cardiac death (SCD) representing the most frequent of all nontraumatic deaths. We evaluated the possible effect of acclimatization in reduction of SCD during high-altitude sojourns. METHODS: This was a retrospective cohort study involving all deaths (N = 559) that occurred during mountain activities in Austria from 1985 through 1993. Baseline patient demographics, cardiovascular comorbidities, smoking history, family history of SCD, sleeping altitude, annual mountaineering frequency, and physical activity on the day of SCD were included in a questionnaire previously used in a pilot study. RESULTS: Data from 301 of 599 individuals without prespecified exclusions were available for analysis (79% of eligible cohort). Sudden cardiac deaths happened mostly around noon (29%), and mean altitude at which SCDs occurred was 1,710 ± 501 m. When sleeping altitude was divided into quartiles (<700 m, 700-999 m, 1,000-1,299 m, and >1,299 m), the odds ratio for SCD on the first day at altitude when sleeping below 700 m was 5.7 (95% CI 2.8-11.6) as compared with sleeping above 1,299 m. CONCLUSION: For males >34 years, those with history of coronary artery disease and/or prior infarction, and those unaccustomed to physical activity at altitude, sleeping at moderate altitude before exercising at altitude may reduce the risk of SCD.

A risk score for predicting coronary artery disease in women with angina pectoris and abnormal stress test finding.

Women with angina pectoris and abnormal stress test findings commonly have no epicardial coronary artery disease (CAD) at catheterization. The aim of the present study was to develop a risk score to predict obstructive CAD in such patients. Data were analyzed from 337 consecutive women with angina pectoris and abnormal stress test findings who underwent cardiac catheterization at our center from 2003 to 2007. Forward selection multivariate logistic regression analysis was used to identify the independent predictors of CAD, defined by ≥50% diameter stenosis in ≥1 epicardial coronary artery. The independent predictors included age ≥55 years (odds ratio 2.3, 95% confidence interval 1.3 to 4.0), body mass index <30 kg/m(2) (odds ratio 1.9, 95% confidence interval 1.1 to 3.1), smoking (odds ratio 2.6, 95% confidence interval 1.4 to 4.8), low high-density lipoprotein cholesterol (odds ratio 2.9, 95% confidence interval 1.5 to 5.5), family history of premature CAD (odds ratio 2.4, 95% confidence interval 1.0 to 5.7), lateral abnormality on stress imaging (odds ratio 2.8, 95% confidence interval 1.5 to 5.5), and exercise capacity <5 metabolic equivalents (odds ratio 2.4, 95% confidence interval 1.1 to 5.6). Assigning each variable 1 point summed to constitute a risk score, a graded association between the score and prevalent CAD (ptrend <0.001). The risk score demonstrated good discrimination with a cross-validated c-statistic of 0.745 (95% confidence interval 0.70 to 0.79), and an optimized cutpoint of a score of ≤2 included 62% of the subjects and had a negative predictive value of 80%. In conclusion, a simple clinical risk score of 7 characteristics can help differentiate those more or less likely to have CAD among women with angina pectoris and abnormal stress test findings. This tool, if validated, could help to guide testing strategies in women with angina pectoris.