Joint effect of highly-sensitive cardiac troponin T and ankle-brachial index on incident cardiovascular events: The MESA and CHS.

Background: Elevated highly-sensitive cardiac troponin-T (hs-cTnT≥14 ng/L) and low ankle-brachial index (ABI<0.9) are risk factors for atherosclerotic cardiovascular diseases (ASCVD) but their joint effect on the risk of ASCVD events is unknown. Methods: We used data from the two population-based cohort studies, the Multi-Ethnic study of Atherosclerosis (MESA) and Cardiovascular Heart Study (CHS) among 10,897 participants free of CVD events at baseline (mean age 66.3 years, 44.7% males). Incident ASCVD was defined as CHD (fatal/non-fatal MI or revascularization), transient ischemic attack, or stroke,. Hazard ratio (HR) and 95% CI was calculated from a Cox regression model. Interaction on the additive scale was assessed using relative excess risk due to interaction (RERI) and interaction on the multiplicative scale was assessed by Likelihood ratio (LR) test. Results: At baseline (2000-2002 for MESA and 1989-1990 for CHS), 10.2% of participants had elevated hs-cTnT and 7.5% had low ABI. During a median follow-up of 13.6 years (interquartile range, 7.5-14.7 years), there were 2590 incident ASCVD and 1542 incident CHD events. The hazard of CHD and ASCVD was higher in participants with both elevated hs-cTnT and low ABI [HR(95% CI): CHD: 2.04 (1.45, 2.88), ASCVD: 2.05 (1.58, 2.66)] than those with only elevated hs-cTnT [CHD: 1.65 (1.37, 1.99), ASCVD: 1.67 (1.44, 1.99)] or only low ABI [CHD: 1.87 (1.52, 2.31), ASCVD: 1.67 (1.42, 1.97)]. Antagonistic multiplicative interaction was observed for CHD (LR test p-value=0.042) but not for ASCVD (LR test p-value =0.08). No significant additive interaction was detected for CHD and ASCVD (RERI p-value ≥0.23). Conclusion: The observed joint effect of elevated cTnT and low ABI on ASCVD risk was smaller (i.e., antagonistic interaction) than that expected by the combined independent effects of each risk factor.

Metabolic Syndrome: An Evolving Clinical Construct.

Metabolic syndrome (MetS), a clustering of metabolic risk factors, identifies individuals at increased risk of diabetes and cardiovascular disease (CVD). Measurement of waist circumference, high-density lipoprotein-cholesterol, triglycerides, blood pressure and fasting blood glucose are easily obtained in the clinic. At any level of low-density lipoprotein-cholesterol, presence of MetS increases the risk of adverse CVD outcomes including bothatherosclerotic CVD and atrial fibrillation. The MetS construct should focus the clinician on recommending behavioral lifestyle modification as this improves all of its components. The challenge, however, has been the lack of a standardized approach to achieve effective and sustained lifestyle modification in clinical practice. We briefly review various approaches useful to the clinician in counseling such patients. These include group lifestyle programs and emerging mobile technology. Technology alone may not be sufficient, but as an adjunct has the promise to improve low rates of behavioral change currently seen with traditional programs.

Fasting or Nonfasting Lipid Measurements: It Depends on the Question.

In the 2013 American College of Cardiology (ACC)/American Heart Association Guideline (AHA) on the Treatment of Blood Cholesterol to Reduce Atherosclerotic Cardiovascular Risk in Adults, low-density lipoprotein cholesterol treatment thresholds have been replaced with a focus on global risk. In this context, we re-examine the need for fasting lipid measurements in various clinical scenarios including estimating initial risk for atherosclerotic cardiovascular disease in a primary prevention patient; screening for familial lipid disorders in a patient with a strong family history of premature atherosclerotic cardiovascular disease or genetic dyslipidemia; clarifying a diagnosis of metabolic syndrome so it can be used to make lifestyle counseling more effective; assessing residual risk in a treated patient; diagnosing and treating patients with suspected hypertriglyceridemic pancreatitis; or diagnosing hypertriglyceridemia in patients who require therapy for other conditions that may further elevate triglycerides. Posing a specific question can aid the clinician in understanding when fasting lipids are needed and when nonfasting lipids are adequate.

'Take as directed'--strategies to improve adherence to cardiac medication.

In patients with cardiovascular diseases, adherence to medication is a fundamental prerequisite for pharmacological therapy to be effective. Nonadherence to medication is a major public health problem that compromises the effectiveness of therapies and results in suboptimal clinical outcomes. The behaviour of nonadherence is complex and is strongly influenced by an interaction between various factors, such as patient education, communication between patients and physicians, drug dosing schedules, and access to health care. Interventions have been implemented to target these barriers to adherence; however, individual interventions have generally been associated with fairly modest improvements in adherence. Financial incentive schemes and modern technology, such as mobile telephone applications, are being harnessed as novel strategies to improve adherence. Ultimately, multifaceted strategies tailored to individual patients are likely to be required to improve long-term adherence to medication and consequently enhance patient health.