Study design: National Registry of Cardiopulmonary Resuscitation (NRCPR), a multicenter prospective cohort.
Setting: 369 U.S. hospitals providing acute care.
Synopsis: Data from NRCPR relating to 6,789 cardiac arrests secondary to ventricular fibrillation or pulseless ventricular tachycardia, at 369 hospitals in hospitalized adults were analyzed. Delayed defibrillation was defined as occurring more than two minutes from the identification of ventricular fibrillation or pulseless ventricular tachycardia to the administration of the first shock to the patient.
Delayed defibrillation occurred in 2,045 (30.1%) subjects. A lower proportion of subjects who received delayed defibrillation (22.2%) compared with those who received defibrillation in two minutes or less (39.3%) survived to hospital discharge. This was statistically significant (adjusted odds ratio [OR] 0.48, 95% CI 0.42 to 0.54; p<0.01).
Bottom line: This study not only reported that delayed defibrillation was prevalent in adult hospitalized patients, but also reinforced the importance of defibrillation within two minutes of identification of cardiac arrest secondary to ventricular fibrillation and pulseless ventricular tachycardia for better survival outcomes.
Citation: Chan PS, Krumholz HM, Nichol G, Nallamothu BK. Delayed time to defibrillation after in-hospital cardiac arrest. N Engl J Med. 2008;358(1):9-17.
Does Right-Ventricle Enlargement in Acute PE Increase In-hospital Death From PE or All-cause Mortality?
Background: Previous studies have shown conflicting results regarding the risk of death with right-ventricular enlargement in acute pulmonary embolism (PE). The role of thrombolysis in hemodynamically stable patients with acute PE and right-ventricular enlargement remains controversial.
Study design: Retrospective analysis of prospective cohort study.
Setting: Academic centers housing inpatients and outpatients in the United States and Canada.
Synopsis: Patients enrolled in PIOPED II who were diagnosed with acute PE and had multidetector computed tomographic (CT) angiography were retrospectively reviewed for the presence of right-ventricular enlargement. Study determined that 181 patients had PE and a CT, and 157 were adequate for measurement of right-ventricular size. PE treatment was anticoagulation in 138, anticoagulation and inferior vena cava filter in 15, inferior vena cava filter alone in two, and thrombolysis in two.
Right-ventricular enlargement was found in 78 (50%) patients; 76 were treated with anticoagulation alone or in combination with inferior vena cava filter. For patients with and without right-ventricular enlargement, there was no difference in in-hospital death from PE (0% vs. 1.3%) or all-cause mortality (2.6% vs. 2.5%). The results were unchanged when examined for septal motion abnormality and previous cardiopulmonary disease.
Bottom line: In hemodynamically stable patients with acute pulmonary embolism, right ventricular enlargement does not increase mortality. Further, thrombolytic therapy is unlikely to improve outcomes.
Citation: Stein PD, Beemath A, Matti F, et al. Enlarged right ventricle without shock in acute pulmonary embolus: prognosis. Am J Med. 2008;121:34-42.
What Are Short-term Thromboembolism, Hemorrhage Risks When Interrupting Warfarin Therapy for Procedures?
Background: The risks of thromboembolism and hemorrhage during the periprocedural interruption of warfarin therapy are not known. The risks and benefits of heparin bridging therapy are not well described.
Study design: Multicenter, prospective, observational cohort study.
Setting: Community-based physician practices.
Synopsis: Patients were eligible if they were on long-term warfarin and underwent outpatient procedures requiring interruption of therapy. The primary outcomes were thromboembolism or hemorrhage within 30 days of therapy interruption. In all, 1,024 eligible patients (7.1% considered high risk) had 1,293 interruptions of warfarin therapy. The most common procedures were colonoscopy (25.1%), oral or dental surgery (24.9%), and ophthalmologic surgery (8.9%). Warfarin interruption was five or fewer days in 83.8% of episodes.
Thromboembolism occurred in seven (0.7%) patients, and major or clinically significant bleeding occurred in 23 (0.6%, and 1.7%, respectively) patients. Periprocedural bridging with heparin was used in 88 (8.6%) patients. Of the patients who received periprocedural heparin therapy, none had thromboembolism, and 14 (13%) had bleeding episodes.