Ariel Diaz

Innovative program to increase physical activity following an acute coronary syndrome: Randomized controlled trial

OBJECTIVE To evaluate the impact of a socio-cognitive intervention associated with a pedometer-based program on physical activity, cardiovascular risk factors and self-efficacy expectation during one year following an acute coronary syndrome. METHODS Sixty-five subjects were randomized during hospitalization in an experimental or a usual care group. Average steps/day was measured every 3 months until one year following discharge. Other dependent variables were measured at baseline, 6 and 12 months follow-up. RESULTS There were 32 patients in the experimental group and 33 patients in the usual care group. Group characteristics were comparable. At baseline, averages steps/day were similar between groups (5845±3246 vs. 6097±3055 steps/day; p=0.812). At 3-month follow-up, both groups increased their averages steps/day (p<0.05). This increase was higher in the experimental group (3388±844 vs. 1934±889 steps/day; p<0.001). At 12-month, interaction effects (group×time) in physical activity and waist circumference were different between groups (p<0.05), whereas self-efficacy expectation increased in both groups similarly (p<0.05). CONCLUSION The intervention is useful to improve average steps/day and waist circumference during the first year following an acute coronary syndrome. PRACTICE IMPLICATIONS This study supports development of the home-based cardiac rehabilitation program using socio-cognitive intervention associated with a pedometer after an acute coronary syndrome.

Effectiveness of a Pedometer-Based Program Using a Socio-cognitive Intervention on Physical Activity and Quality of Life in a Setting of Cardiac Rehabilitation

BACKGROUND Physical activity contributes to improve health and quality of life. However, the prevalence of sedentary lifestyle is elevated after an acute coronary syndrome. METHODS A randomized controlled trial was performed to evaluate the impact of a pedometer-based program associated with a socio-cognitive intervention on physical activity behaviour, cardiovascular risk factors, and quality of life during the year after an acute coronary syndrome event. During hospitalization, we randomized 32 patients to an experimental group and 33 patients to a usual care group. The experimental intervention included 6 consultations with a clinical nurse specialist during 12 months. RESULTS Groups characteristics were comparable. At baseline, the percentage of participants considered in the active range category was similar between groups (31% vs 41%; P = 0.915). However, the proportion of participants who were still active was greater in the experimental group than in the usual care group at 6, 9, and 12 months follow-up (75% vs 41%; 68% vs 36%, and 83% vs 55%, respectively; P < 0.05). After 12 months, changes in overall quality of life and in health and the functioning scores were different between groups (interaction effects [groups by time] P = 0.048 and P = 0.036, respectively). CONCLUSIONS The use of a pedometer concomitantly with a socio-cognitive intervention improves adherence to physical activity and quality of life during the year after an acute coronary syndrome event. This finding is relevant because physical activity and quality of life are a great concern in preventive cardiology. These results support applying this innovative approach in cardiac rehabilitation programs.

CKM and LILRB5 Are Associated With Serum Levels of Creatine Kinase

Background—Statins (HMG-CoA reductase inhibitors) are the most prescribed class of lipid-lowering drugs for the treatment and prevention of cardiovascular disease. Creatine kinase (CK) is a commonly used biomarker to assist in the diagnosis of statin-induced myotoxicity but the normal range of CK concentrations is wide, which limits its use as a diagnostic biomarker. Methods and Results—We conducted a genome-wide association study of serum CK levels in 3412 statin users. Patients were recruited in Quebec, Canada, and genotyped on Illumina Human610-Quad and an iSelect panel enriched for lipid homeostasis, hypertension, and drug metabolism genes. We found a strong association signal between serum levels of CK and the muscle CK (CKM) gene (rs11559024: P=3.69×10−16; R2=0.02) and with the leukocyte immunoglobulin-like receptor subfamily B member 5 (LILRB5) gene (rs2361797: P=1.96×10−10; R2=0.01). Genetic variants in those 2 genes were independently associated with CK levels in statin users. Results were successfully replicated in 5330 participants from the Montreal Heart Institute Biobank in statin users for CKM (rs11559024: P=4.32×10−16; R2=0.02) and LILRB5 (rs12975366 P=4.45×10−10; R2=0.01) and statin nonusers (P=4.08×10−7, R2=0.01; P=3.17×10−9, R2=0.02, respectively). Conclusions—This is the first genome-wide study to report on the underlying genetic determinants of CK variation in a population of statin users. We found statistically significant association for variants in the CKM and LILRB5 genes.

Impact of revascularization in patients with sustained ventricular arrhythmias, prior myocardial infarction, and preserved left ventricular ejection fraction.

BACKGROUND The impact of revascularization on recurrent ventricular arrhythmias (VAs) in patients with coronary artery disease and relatively preserved left ventricular ejection fraction (LVEF) is unknown. OBJECTIVE The purpose of this study was to determine the impact of revascularization on recurrent VAs or death. METHODS A cohort study was conducted on consecutive patients with prior myocardial infarction and LVEF ≥40% presenting with a first clinical sustained VA in the absence of an acute coronary syndrome. The impact of revascularization on recurrent VAs and all-cause mortality was assessed. RESULTS A total of 274 patients (mean age 66.1 ± 9.7 years, 85.4% male, mean LVEF 48.3% ± 7.2%) were included in the study. Eight-eight patients (32.1%) underwent coronary revascularization. During mean follow-up of 6.2 ± 5.1 years, 140 (51.1%) died or had recurrent sustained VAs or appropriate implantable-cardioverter defibrillator therapy. Revascularization was not associated with a significantly lower rate of recurrent VAs or death (multivariable hazard ratio [HR] 0.86, 95% confidence interval [CI] 0.60-1.24, P = .43) regardless of whether it was complete or incomplete (HR 0.65, 95% CI 0.25-1.69, P = .37) or was performed by percutaneous or surgical means (HR 1.02, 95% CI 0.53-1.94, P = .96). An implantable-cardioverter defibrillator was associated with a significant reduction in mortality (HR 0.23, 95% CI 0.09-0.55, P = .001). CONCLUSION Patients with prior myocardial infarction and LVEF ≥40% who present with sustained VAs in the absence of an acute coronary syndrome remain at high risk for recurrent VAs and all-cause death. Coronary revascularization does not systemically mitigate this risk.

Use of troponin assay 99th percentile as the decision level for myocardial infarction diagnosis

Background The Universal Definition of Myocardial Infarction recommends the 99th percentile concentration of cardiac troponin in a normal reference population as part of the decision threshold to diagnose type 1 spontaneous myocardial infarction. Adoption of this recommendation in contemporary worldwide practice is not well known. Methods We performed a cohort study of 276 hospital laboratories in 31 countries participating in the National Heart, Lung, and Blood Institute–sponsored International Study of Comparative Health Effectiveness with Medical and Invasive Approaches trial. Each hospital laboratorys troponin assay manufacturer and model, the recommended assays 99th percentile upper reference limit (URL) from the manufacturers package insert, and the troponin concentration used locally as the decision level to diagnose myocardial infarction were ascertained. Results Twenty‐one unique troponin assays from 9 manufacturers were used by the surveyed hospital laboratories. The ratio of the troponin concentration used locally to diagnose myocardial infarction to the assay manufacturer–determined 99th percentile URL was <1 at 19 (6.6%) laboratories, equal to 1 at 91 (31.6%) laboratories, >1 to ≤5 at 101 (35.1%) laboratories, >5 to ≤10 at 34 (11.8%) laboratories, and >10 at 43 (14.9%) laboratories. The variability in troponin decision level for myocardial infarction relative to the assay 99th percentile URL was present for laboratories in and outside of the United States, as well as for high‐ and standard‐sensitivity assays. Conclusions There is substantial hospital‐level variation in the troponin threshold used to diagnose myocardial infarction; only one‐third of hospital laboratories currently follow the Universal Definition of Myocardial Infarction consensus recommendation for use of troponin concentration at the 99th percentile of a normal reference population as the decision level to diagnose myocardial infarction. This variability across laboratories has important implications for both the diagnosis of myocardial infarction in clinical practice as well as adjudication of myocardial infarction in clinical trials.

SUBSTANTIAL VARIABILITY BETWEEN LABORATORIES IN TROPONIN DECISION LEVEL FOR DIAGNOSIS OF MYOCARDIAL INFARCTION AND ASSAY 99TH PERCENTILE: FINDINGS FROM THE INTERNATIONAL STUDY OF COMPARATIVE HEALTH EFFECTIVENESS WITH MEDICAL AND INVASIVE APPROACHES (ISCHEMIA) TRIAL

The Third Universal Definition of Myocardial Infarction (MI) designates an increase in cardiac troponin concentration (cTn) > 99th percentile of a normal reference population as the decision level for MI diagnosis. The variability among hospitals in the lab-determined cTn level to diagnose MI [cTn

Rationale, design, and preliminary results of the Quebec Warfarin Cohort Study

Over‐ and undercoagulation with warfarin are associated with hemorrhagic and thromboembolic events, respectively. Genetic and clinical factors affect warfarin response, and the causes of this variability remain unclear. We present descriptive statistics and test for predictors of poor anticoagulation control. The Quebec Warfarin Cohort (QWC) comprises 1059 new warfarin users, with prospective follow‐up using telephone questionnaires every 3 months for 1 year, and using healthcare administrative databases (RAMQ and Med‐Echo) for 5 years prior to cohort entry and up to 10 years following active patient participation. Genetic material was collected, and genotyping of CYP2C9 and VKORC1 genes was conducted. Measured outcomes included the percentage of time patients spent within therapeutic range, anticoagulation control, warfarin dose, bleeding, and thromboembolic events. We report baseline characteristics and outcomes after 1 year of follow‐up. Poor anticoagulation control was defined as time in therapeutic range <60% in the 3‐ to 12‐month interval. Participants had a mean age of 71 years, and 62% were men. The most common indication for warfarin was atrial fibrillation (87%). Mean time in therapeutic range was 56% (±25%) in the 3 months following warfarin initiation, and 70% (±21%) in the 3‐ to 12‐month interval. During follow‐up, the rate of stroke or systemic embolism was 1.8 events per 100 person‐years; for major bleeding events, 3.3 events per 100 person‐years. Independent predictors of poor anticoagulation control were chronic kidney disease, heart failure, dyslipidemia, and age. The QWC represents a good research cohort to investigate clinical and genetic factors in a warfarin‐anticoagulated population.