The role of cardiac testing with the 0/1-hour high-sensitivity cardiac troponin algorithm evaluating for acute myocardial infarction.

BACKGROUND: The role of cardiac testing in the 3 zones (rule-out, observation, and rule-in) of the 0/1-hour algorithm to evaluate for acute myocardial infarction (AMI) has not been well studied. This study evaluated the 0/1-hour algorithm with a high-sensitivity cardiac troponin (hs-cTnI) assay and investigated cardiac testing in the 3 zones. METHODS: Patients (n = 552) at a single urban center were enrolled if they were evaluated for AMI. Blood samples were obtained at presentation, 1 hour, and 3 hours for hs-cTnI. Follow-up at 30 to 45 days for death/AMI was done. The results of echocardiograms, stress testing, and coronary angiography were recorded. RESULTS: In total, 45 (8.2%) had AMI (27 Type 1 and 18 Type 2) during the index hospitalization while at follow-up death/AMI occurred in 11 (2.0%) of patients. The rule-out algorithm had a negative predictive value for AMI of 99.6% while the rule-in zone had a positive predictive value of 56.6%. The MACE rate at follow-up was 0.4% for those in the rule-out group. There were 6/95 (6.3%) abnormal stress tests in the rule-out zone and 4 of these were false positives. CONCLUSIONS: The 0/1-hour algorithm had high diagnostic sensitivity and negative predictive value for AMI, and adverse events were very low in patients in the rule-out zone. Noninvasive testing in rule-out zone patients had low diagnostic yield.

Unprotected discharge: absence of stroke prevention strategies in patients with atrial fibrillation admitted for bleeding.

PURPOSE: Patients with atrial fibrillation or flutter (AF) on anticoagulation (AC) for stroke prevention are at an increased risk of bleeding. A common clinical dilemma is deciding when to safely restart AC following a bleed. Although studies have shown better outcomes with re-initiation of AC after hemostasis, there are clinical barriers to restarting AC. Left atrial appendage occlusion (LAAO) is a safe and efficacious alternative for patients who are unable to tolerate AC following major bleeding. We aimed to evaluate the rate of stroke prevention strategies instituted at time of discharge in patients with AF on AC who had been hospitalized for a bleeding event. METHODS: We retrospectively identified patients with AF on AC admitted for bleeding between January 2016 and August 2019. The type of AC, form of bleeding, and CHA2DS2VASc were collected. Stroke prevention strategies upon discharge and at 3 months were noted. RESULTS: One hundred seventy-four patients with AF on AC were hospitalized with a bleeding event, of which 10.9% died. Among patients who survived, AC was restarted in 45.2% of patients, 9.7% were referred for LAAO, and 45.1% were discharged without stroke prevention strategy. At 3 months, 32.6% of patients still had no documented stroke prophylaxis. Those referred for LAAO had, on average, higher CHA2DS2VASc (5 ± 1 vs 4 ± 1, p = 0.007). CONCLUSIONS: A significant number of patients with AF hospitalized for bleeding were discharged with no plan for stroke prophylaxis. Despite its safety and efficacy, LAAO appears to be an underutilized alternative in AF patients with high bleeding risk.

Diffuse B Cell Lymphoma Leading to Complete Heart Block: Is This Transient or Permanent?

BACKGROUND Cardiac lymphomas can lead to heart block through tumor disruption of the cardiac conduction system. It is reported that with cardiac tumor treatment, conduction abnormalities can resolve. We present a case of cardiac lymphoma resulting in complete heart block requiring a pacemaker, followed by reduction of the pacing burden after chemotherapy. CASE REPORT A 72-year-old woman with a medical history of hypertension, hypothyroidism, and persistent atrial fibrillation presented with dyspnea on exertion and fatigue for 2 weeks. Electrocardiography revealed complete heart block with junctional bradycardia of 48 beats per min. Transthoracic echocardiography demonstrated preserved left ventricular systolic function along with a large mass (3.6×3.7 cm). An endomyocardial biopsy was consistent with diffuse large B cell lymphoma, and the cardiac involvement was thought to be secondary based on positron emission tomography scan findings. Her clinical course was complicated by an episode of syncope deemed to be due to transient asystole, and an urgent single-chamber permanent pacemaker was implanted. Chemotherapy was initiated with R-CHOP, and, following the second cycle of chemotherapy, a positron emission tomography scan revealed no increased radiotracer uptake and thus resolution of all tumors. An echocardiogram 6 weeks after chemotherapy showed complete resolution of the cardiac mass. Subsequent serial pacemaker checks demonstrated improvement of atrioventricular nodal function as manifested by reduced pacing burden. CONCLUSIONS Lymphoma with cardiac involvement can lead to conduction abnormalities, including CHB, and heart block in the setting of these tumors may be reversible with appropriate therapy; however, implantation of a pacemaker remains inevitable is some cases.