Randomized Comparison of a CrossBoss First Versus Standard Wire Escalation Strategy for Crossing Coronary Chronic Total Occlusions: The CrossBoss First Trial.

OBJECTIVES: The authors performed a multicenter, randomized-controlled, clinical trial comparing upfront use of the CrossBoss catheter versus antegrade wire escalation for antegrade crossing of coronary chronic total occlusions. BACKGROUND: There is equipoise about the optimal initial strategy for crossing coronary chronic total occlusions. METHODS: The primary endpoints were the time required to cross the chronic total occlusion or abort the procedure and the frequency of procedural major adverse cardiovascular events. The secondary endpoints were technical and procedural success, total procedure time, fluoroscopy time required to cross and total fluoroscopy time, total air kerma radiation dose, total contrast volume, and equipment use. RESULTS: Between 2015 and 2017, 246 patients were randomized to the CrossBoss catheter (n = 122) or wire escalation (n = 124) at 11 U.S. centers. The baseline clinical and angiographic characteristics of the study groups were similar. Technical and procedural success were 87.8% and 84.1%, respectively, and were similar in the 2 groups. Crossing time was similar: 56 min (interquartile range: 33 to 93 min) in the CrossBoss group and 66 min (interquartile range: 36 to 105 min) in the wire escalation group (p = 0.323), as was as the incidence of procedural major adverse cardiovascular events (3.28% vs. 4.03%; p = 1.000). There were no significant differences in the secondary study endpoints. CONCLUSIONS: As compared with wire escalation, upfront use of the CrossBoss catheter for antegrade crossing of coronary chronic total occlusions was associated with similar crossing time, similar success and complication rates, and similar equipment use and cost.

The natural history of lone atrial flutter.

BACKGROUND: The natural history of atrial flutter is not well defined. OBJECTIVE: To report the risk for stroke, conversion to atrial fibrillation, and anticoagulation for lone atrial flutter. DESIGN: Retrospective cohort analysis. SETTING: A clinically based longitudinal study of inpatients and outpatients with atrial flutter. PATIENTS: The authors compared the stroke rate in 59 patients with atrial flutter with rates in a sample in which age- and sex-specific ischemic cerebrovascular event rates were determined and in a sample of nonhypertensive patients with lone atrial fibrillation. The risk for developing atrial fibrillation after presenting with atrial flutter is also reported. MEASUREMENTS: Electrocardiograms and clinical data were collected and reviewed for each study participant. RESULTS: After adjustment for age and sex, patients with atrial flutter had a higher incidence of thromboembolic events than the sample control patients and patients with atrial fibrillation. Atrial fibrillation developed in 56% of patients with atrial flutter. CONCLUSIONS: Lone atrial flutter has a stroke risk at least as high as lone atrial fibrillation and carries a higher risk for subsequent development of atrial fibrillation than in the general population. Anticoagulation should be considered for all patients with atrial flutter who are older than 65 years of age.

Effect of long-term hormone replacement therapy on coronary endothelial function in postmenopausal women.

OBJECTIVES: To determine the difference in endothelial function between premenopausal and postmenopausal women and to determine whether hormone replacement therapy (HRT) is associated with an improvement in coronary endothelial function. PATIENTS AND METHODS: Women undergoing coronary physiology studies for chest pain at the Mayo Clinic In Rochester, Minn, between December 1992 and April 2002 underwent assessment of coronary endothelium-independent and -dependent function with intracoronary administration of adenosine and acetylcholine, respectively. The coronary diameters, coronary blood flows, and coronary velocity reserves were measured. RESULTS: A total of 270 women (89 premenopausal and 181 postmenopausal) participated in the study. Endothelium-dependent coronary blood flow change (baseline to peak flow) in response to acetylcholine (10(-4), 10(-5), and 10(-4) mol/L) was lower in postmenopausal women compared with premenopausal women (39.7% vs 72.9%, P = .03). There was no significant difference between the postmenopausal women receiving and not receiving HRT with regard to percent change in coronary diameter (-21.8% vs -13.9%, P = .15), percent change in coronary blood flow (37.3% vs 42.7%, P = .74), or coronary velocity reserve (2.7 vs 2.7, P = .82). CONCLUSION: This study shows that the postmenopausal state is associated with a greater abnormality in coronary endothelial function at the level of the microcirculation. Moreover, HRT status was not associated with an improvement in coronary endothelial function in postmenopausal women.