A randomized clinical trial to evaluate the efficacy and safety of rivaroxaban in patients with bioprosthetic mitral valve and atrial fibrillation or flutter: rationale and design of the RIVER trial

Background The efficacy and safety of rivaroxaban in patients with bioprosthetic mitral valves and atrial fibrillation or flutter remain uncertain. Design RIVER was an academic-led, multicenter, open-label, randomized, non-inferiority trial with blinded outcome adjudication that enrolled 1005 patients from 49 sites in Brazil. Patients with a bioprosthetic mitral valve and atrial fibrillation or flutter were randomly assigned (1:1) to rivaroxaban 20 mg once daily (15 mg in those with creatinine clearance <50 mL/min) or dose-adjusted warfarin (target international normalized ratio 2.0-30.); the follow-up period was 12 months. The primary outcome was a composite of all-cause mortality, stroke, transient ischemic attack, major bleeding, valve thrombosis, systemic embolism, or hospitalization for heart failure. Secondary outcomes included individual components of the primary composite outcome, bleeding events, and venous thromboembolism. Summary RIVER represents the largest trial specifically designed to assess the efficacy and safety of a direct oral anticoagulant in patients with bioprosthetic mitral valves and atrial fibrillation or flutter. The results of this trial can inform clinical practice and international guidelines.

A randomized clinical trial to evaluate the efficacy and safety of rivaroxaban in patients with bioprosthetic mitral valve and atrial fibrillation or flutter: Rationale and design of the RIVER trial.

The efficacy and safety of rivaroxaban in patients with bioprosthetic mitral valves and atrial fibrillation or flutter remain uncertain. DESIGN: RIVER was an academic-led, multicenter, open-label, randomized, non-inferiority trial with blinded outcome adjudication that enrolled 1005 patients from 49 sites in Brazil. Patients with a bioprosthetic mitral valve and atrial fibrillation or flutter were randomly assigned (1:1) to rivaroxaban 20 mg once daily (15 mg in those with creatinine clearance <50 mL/min) or dose-adjusted warfarin (target international normalized ratio 2.0-30.); the follow-up period was 12 months. The primary outcome was a composite of all-cause mortality, stroke, transient ischemic attack, major bleeding, valve thrombosis, systemic embolism, or hospitalization for heart failure. Secondary outcomes included individual components of the primary composite outcome, bleeding events, and venous thromboembolism. SUMMARY: RIVER represents the largest trial specifically designed to assess the efficacy and safety of a direct oral anticoagulant in patients with bioprosthetic mitral valves and atrial fibrillation or flutter. The results of this trial can inform clinical practice and international guidelines.

Symptoms awareness, emergency medical service utilization and hospital transfer delay in myocardial infarction.

BACKGROUND: The length of time between symptom onset and reperfusion therapy in patients with ST-segment elevation acute myocardial infarction (STEMI) is a key determinant of mortality. Information on this delay is scarce, particularly for developing countries. The objective of the study is to prospectively evaluate the individual components of reperfusion time (RT) in patients with STEMI treated at a University Hospital in 2012. METHODS: Medical records were reviewed to determine RT, its main (patient delay time [PDT] and system delay time [SDT]) and secondary components and hospital access variables. Cognitive responses were evaluated using a semi-structured questionnaire. RESULTS: A total of 50 patients with a mean age of 59 years (SD = 10.5) were included, 64% of whom were male. The median RT was 430 min, with an interquartile range of 315-750 min. Regarding the composition of RT in the sample, PDT corresponded to 18.9% and SDT to 81.1%. Emergency medical services were used in 23.5% of cases. Patients treated in intermediate care units showed a significant increase in SDT (p = 0.008). Regarding cognitive variables, PDT was approximately 40 min longer among those who answered "I didn't think it was serious" (p = 0.024). CONCLUSIONS: In a Brazilian tertiary public hospital, RT was higher than that recommended by international guidelines, mainly because of long SDT, which was negatively affected by time spent in intermediate care units. Emergency Medical Services underutilization was noted. A patient's low perception of severity increased PDT.

Life-threatening cardiac manifestations of pheochromocytoma.

Pheochromocytoma is a catecholamine-secreting tumor of the adrenal glands, usually with benign manifestations, whose typical clinical presentation includes the triad of headache, palpitations and diaphoresis. However, a wide range of signs and symptoms may be present. In the cardiovascular system, the most common signs are labile hypertension and sinus tachycardia. Systolic heart failure and ST-segment deviations mimicking myocardial infarction have also been reported, as well as QT interval prolongation and, rarely, ventricular tachycardia. We describe a challenging diagnosis of pheochromocytoma with many cardiovascular manifestations, which could have been missed due to the absence of typical symptoms.

Simultaneous epicardial and endocardial substrate mapping and radiofrequency catheter ablation as first-line treatment for ventricular tachycardia and frequent ICD shocks in chronic chagasic cardiomyopathy.

BACKGROUND AND AIMS: Slow conduction scarred areas are related with ventricular tachycardia (VT) arrhythmogenesis in nonischemic cardiomyopathy. The purpose of this study was to characterize the substrate in both epicardial and endocardial surfaces of the left ventricle and to evaluate the effectiveness of substrate mapping and ablation for VT in Chagas cardiomyopathy. METHODS AND RESULTS: Seventeen patients were evaluated prospectively using a simultaneous epicardial and endocardial electroanatomical substrate mapping and ablation. With a mean of 201 +/- 94 epicardial and 169 +/- 77 endocardial points, the epicardial voltage areas < or =0.5 mV were 56.8 +/- 40.6 (range 4.4 to 154.8 cm(2)) as compared to 22.5 +/- 15.8 cm(2) (range 5.4 to 61.0 cm(2); p = 0.004) in the endocardium. Analyzing the epicardial surface, there was a strong correlation between the bipolar voltage electrograms and the electrogram duration at the epicardium during sinus rhythm (r = 0.897, p < 0.0001). Acute success was obtained in 83.3% of patients with no serious complications. At the end of follow-up from 14 patients with acute success, 11 (78.6%) had been event-free based on implantable cardioverter defibrillator (ICD) interrogation logs. CONCLUSION: Chronic Chagas cardiomyopathy patients have larger epicardial as compared to endocardial substrate areas. Combined epicardial endocardial substrate mapping and ablation during sinus rhythm proves effective in preventing VT recurrences and appropriate ICD therapies.

Anticoagulation for atrial fibrillation: underutilization in a Brazilian tertiary outpatient clinic.

Despite a clear benefit of anticoagulation in patients with atrial fibrillation for the prevention of stroke, treatment rates are disappointingly low in clinical practice in the industrialized countries. This survey demonstrates similar rates in a Brazilian tertiary outpatient clinic, with only 55% of patients at high risk receiving dose-adjusted warfarin. Poor patient education and health care system limitations are considered important barriers. Strategies to improve treatment rates should target specific problems at each location.

Left atrial tachycardia after circumferential pulmonary vein ablation for atrial fibrillation: electroanatomic characterization and treatment.

OBJECTIVES: The purpose of this study was to evaluate the electroanatomic characteristics of left atrial tachycardia (AT) in a series of patients who underwent circumferential pulmonary vein ablation (CPVA) and to describe the ablation strategy and clinical outcome. BACKGROUND: Circumferential pulmonary vein ablation is an effective treatment for atrial fibrillation. A potential midterm complication is the development of left AT. There are only isolated reports describing mapping and ablation of such arrhythmias. METHODS: Thirteen patients (age 57.4 +/- 8.9 years, five female) underwent mapping and ablation of 14 left ATs via an electroanatomic mapping system a mean of 2.6 +/- 1.6 months after CPVA. RESULTS: Three patients were characterized as having focal AT (cycle length: 266 +/- 35.9 ms). Of 11 macro-re-entrant tachycardias studied in the remaining 10 patients (cycle length: 275 +/- 75 ms), 5 showed single-loop and 6 dual-loop circuits. Re-entrant circuits used the mitral isthmus, the posterior wall, or gaps on previous encircling lines. Such gaps and all three foci occurred anterior to the left superior pulmonary vein or at the septal aspect of the right pulmonary veins. Thirteen of 14 tachycardias (93%) were successfully ablated. CONCLUSIONS: Left AT after CPVA can be due to a macro-re-entrant or focal mechanism. Re-entry occurs most commonly across the mitral isthmus, the posterior wall, or gaps on previous ablation lines. Such gaps and foci occur most commonly at the anterior aspect of the left superior pulmonary vein and at the septal aspect of the right pulmonary veins. These arrhythmias can be successfully mapped and ablated with an electroanatomic mapping system.

Nonsurgical transthoracic epicardial ablation for the treatment of a resistant posteroseptal accessory pathway.

A case of Wolff-Parkinson-White syndrome successfully treated by transcutaneous epicardial radiofrequency ablation is described in a patient with a posteroseptal accessory pathway who had failed prior attempts of conventional endocardial and coronary venous system approaches. Simultaneous endocardial and pericardial space mapping was performed and only ablation from the pericardial space was successful, suggesting an epicardial course of the accessory pathway.