Ivabradine in the Prevention, and Reduction in Size, of Perioperative Myocardial Injury in Patients Undergoing Orthopedic Surgery for Acute Fracture.

BACKGROUND: Perioperative myocardial injury is common after major noncardiac surgery and is associated with adverse outcomes. This study investigated the use of ivabradine in patients undergoing urgent surgery for fracture. METHODS AND RESULTS: This was a prospective, double-blind, placebo-controlled, randomized clinical trial. Participants were enrolled 1:1 into ivabradine or placebo arm, and study drug was commenced before operation and continued for 7 days or until discharge. High-sensitivity troponin I was measured daily using Abbott Alinity analyzer and assay, and heart rate data were obtained using continuous Holter monitoring. A total of 199 patients underwent acute orthopedic surgery, 98 in the ivabradine group and 101 in the placebo group. The mean age was 78.7 years (range, 77.5-79.9 years), with 68% women. The average heart rate was 5 to 11 beats per minute lower in the ivabradine group compared with the placebo group at all time points (P<0.001 for all). There was no statistically significant difference between the ivabradine and placebo groups in the number of patients who had perioperative myocardial injury: 28.6% versus 31.6% (P=0.71). In patients with perioperative myocardial injury, average peak troponin was 168.8 ng/L (±431.2 ng/L) in the ivabradine group and 2094.5 ng/L (±7201.9 ng/L) in the placebo group (P=0.16). There was no statistically significant difference between groups in 30-day mortality, blood pressure, stroke, or major adverse cardiovascular event. CONCLUSIONS: Starting ivabradine preoperatively in elderly patients requiring acute surgery for fracture did not result in a statistically significant difference in the incidence of perioperative myocardial injury. There was no statistically significant difference in morbidity, mortality, or adverse events between treatment groups. REGISTRATION: URL: https://www.anzctr.org.au/; Unique identifier: ACTRN12616001634460p.

Type 2 MI and Myocardial Injury in the Era of High-sensitivity Troponin.

Troponin has been the cornerstone of the definition of MI since its introduction to clinical practice. High-sensitivity troponin has allowed clinicians to detect degrees of myocardial damage at orders of magnitude smaller than previously and is challenging the definitions of MI, with implications for patient management and prognosis. Detection and diagnosis are no doubt enhanced by the greater sensitivity afforded by these markers, but perhaps at the expense of specificity and clarity. This review focuses on the definitions, pathophysiology, prognosis, prevention and management of type 2 MI and myocardial injury. The five types of MI were first defined in 2007 and were recently updated in 2018 in the fourth universal definition of MI. The authors explore how this pathophysiological classification is used in clinical practice, and discuss some of the unanswered questions in this era of availability of high-sensitivity troponin.

Use of Atrial Strain to Predict Atrial Fibrillation After Cerebral Ischemia.

OBJECTIVES: This study sought to identify whether atrial strain could be used as an imaging biomarker to predict atrial fibrillation (AF). BACKGROUND: AF is found in up to 30% of cryptogenic cerebrovascular accidents (CVAs), which themselves account for 30% to 40% of ischemic CVA. METHODS: This observational study evaluated all patients who had an echocardiogram (transthoracic echocardiogram [TTE]) following presentation with cryptogenic CVA from 2010 to 2014. The TTEs were evaluated for reservoir strain (ƐR), contractile strain (ƐCt), and conduit atrial strain (ƐCd) using speckle tracking. Baseline clinical and TTE characteristics of patients who developed AF over 5 years of follow-up and those who did not were compared. The independent and incremental predictive value of atrial strain over established clinical models was assessed. Discriminatory cutpoints were defined using a Classification and Regression Tree (CART) analysis to identify patients at risk of developing AF. RESULTS: Of 538 patients, 61 (11%) developed AF, and this occurred within 2 years in 85% of patients. Patients who developed AF were older, had higher clinical risk scores, had higher LA volume, and had lower atrial strain than did those who did not develop AF. The area under the receiver-operating characteristic curve was 0.85 for ƐR, 0.83 for ƐCt, and 0.76 for ƐCd (all p < 0.001). The nested Cox regression model showed that ƐR (p = 0.03) and ƐCt (p < 0.001) demonstrated independent and incremental predictive value over the clinical risk. CART analysis identified ƐR ≤21.4%, ƐCd >10.4%, and CHARGE-AF (Cohorts for Heart and Aging Research in Genomic Epidemiology Atrial Fibrillation) score >7.8% as discriminatory for AF, with a 13-fold greater hazard of AF (p < 0.001) in patients with increased clinical risk and reduced ƐR. However, validation is needed for these strain cutoffs for detection of AF. CONCLUSIONS: Left atrial strain adds independent and incremental predictive value to current risk-prediction models for AF following cryptogenic CVA. Further studies should examine the implications of these findings for AF monitoring or empiric anticoagulation.