The American College of Cardiology (ACC) held its 2010 annual scientific sessions from March 14 to 16 in Atlanta. The features below highlight some of the news emerging from the ACC scientific sessions. For more information on these items and other research that was presented, go to www.acc.org.
Gender Differences in Cardiac Catheterization
The Particulars: In previous research data, men have been consistently more likely than women to be sent to the cardiac catheterization laboratory after noninvasive cardiovascular imaging tests. In the past, symptoms of suspected heart disease in women have often been dismissed as false positives or misinterpreted. More recently, there has been increased publicity about the underrecognition of heart disease in women, and campaigns have been launched to raise awareness.
Data Breakdown: A study of 1,700 patients recruited from the Study of Myocardial Perfusion and Coronary Anatomy Imaging Roles in Coronary Artery Disease registry was conducted. Patients had no history of heart disease, presented with chest pain, and underwent cardiovascular imaging tests. Tests were abnormal in 30% of women and 22% of men. Overall, 10% of patients in the study cohort were referred to cardiac catheterization within 90 days, with higher rates in women (13%) than men (6%).
Take Home Pearls: Women appear to be twice as likely as men to be referred for cardiac catheterization. Whether the difference in referrals by gender is due to excessive referrals to cardiac catheterization in women or underutilization in men requires further investigation.
Promising New Data on Mitral-Clip Device
The Particulars: Only about 20% of patients with significant mitral regurgitation undergo surgery, and most are managed medically. While drugs may help with symptoms, they typically do not help treat the underlying pathophysiology or disease progression. The Endovascular Valve Edge-to-Edge Repair Study (EVEREST) II was conducted to analyze the safety and efficacy of a novel mitral-clip device (MitraClip, Abbott Laboratories), a percutaneous version of mitral-valve repair. It was hypothesized that the device may lead to fewer early adverse events than traditional valve repair or replacement.
Data Breakdown: The primary safety end points in EVEREST II significantly favored the MitraClip procedure at 30 days. Less than 10% of patients experienced a major adverse event, compared with 57% for those treated surgically. Need for blood transfusions was the primary cause of the safety end point. For the primary efficacy end point, the overall clinical success rate was higher in the surgery group, but the difference statistically met a prespecified noninferiority hypothesis. For the quality-of-life end point specifically, 12-month improvements were similar between the two groups.
Take Home Pearls: The MitraClip procedure appears to be an important therapeutic option for selected patients with significant mitral regurgitation, given the demonstrated safety, effectiveness, and clinical benefit. The device may be as effective an additional option for patients deemed suitable for a percutaneous approach. Close attention to appropriate selection is also key for surgical patients. If approved by the FDA, the clip-based therapy may become a welcome alternative to surgery.
Combination Therapy for Reducing Cardiovascular Events?
The Particulars: Recent data suggest that combination therapy consisting of a fibrate and statin may be of benefit among patients with dyslipidemia, those with high triglyceride levels, and individuals with low HDL-cholesterol levels. The Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial was conducted in 10,251 high-risk patients with type 2 diabetes who were randomly assigned to either intensive or standard glycemic control. In addition, some participants were randomized to either intensive or standard blood-pressure control, while others were randomly assigned to simvastatin plus fenofibrate or simvastatin plus placebo.
Data Breakdown: The glycemic-control ACCORD study was stopped early because of higher mortality in the intensive-glycemic-control group. All patients were then transferred to a standard glycemia-control regimen to analyze blood pressure control. After an average follow-up of 4.7 years, there were 291 major fatal or nonfatal cardiovascular events in the fenofibrate-statin-therapy study arm and 310 events in the statin-therapy-alone arm. The difference in events was not statistically significant. Among the secondary end points, there was also no statistically significant difference between the two treatments.
Take Home Pearls: Findings from the ACCORD trial do not appear to support the use of combination fibrate-statin therapy over statin monotherapy to reduce cardiovascular risk in the majority of patients with type 2 diabetes who are at high risk for cardiovascular disease. Combination therapy with fenofibrate and simvastatin failed to reduce the risk of fatal cardiovascular events, nonfatal myocardial infarction, or nonfatal stroke. Results reinforce the importance of lifestyle modifications in treating type 2 diabetes.
Psoriasis a Risk Factor for CVD
The Particulars: Psoriasis is a common disease, affecting 2% to 3% of people worldwide. The association between psoriasis and cardiovascular disease (CVD) has been suggested in previous literature, but results from these investigations have been ambiguous and debated. Researchers tracked rates of psoriasis, atrial fibrillation, stroke, myocardial infarction, PCI, and death and assessed the incidence of cardiac events in 40,000 patients with mild-to-severe psoriasis, comparing results with those in 4 million people without psoriasis.
Data Breakdown: Patients with severe psoriasis were more likely to experience all of the adverse cardiac events tracked. Individuals with mild psoriasis were more likely to experience atrial fibrillation, stroke, and PCI, even after adjustment for other risk factors. The increased risk of atrial fibrillation and stroke was age-dependent; risk in patients with moderate-to-severe psoriasis was higher in those who were younger than 50. The mechanism behind the observed associations was believed to be coincident inflammation.
Take Home Pearls: Psoriasis appears to be a risk factor for CVD. Patients treated for psoriasis, particularly those with severe psoriasis, should be prioritized for lifestyle changes and screened for dyslipidemia and hypertension. They should also be considered for earlier medical risk-factor interventions for CVD.
Predicting Obstructive Coronary Disease
The Particulars: The role of abdominal aortic calcification (AAC) as a predictor of cardiovascular events has not been well characterized in published research. Investigators conducted a study in which 367 patients who were asymptomatic for coronary disease were analyzed with non-contrast abdominal scans but had a coronary angiography within 1 year of a CT. Exclusion criteria were previous known coronary artery disease (CAD), acute ST-elevation MI at the time of angiography, or previous abdominal aortic surgery.
Data Breakdown: After a median follow-up of 27 months, a univariate analysis showed that increasing AAC was associated with increased mortality. A multivariate analysis showed that AAC added incremental prognostic information over clinical variables, coronary anatomy, and left ventricular function. A second analysis found that patients with obstructed coronaries were older and more likely to have hypertension, diabetes, and high cholesterol. They were also more likely to take aspirin and statin therapy. AAC scores were significantly higher in subjects with obstructive CAD. The ability of AAC to predict obstructive coronary disease had a sensitivity of 96% and a specificity of 31%, with positive and negative predictive values of 58% and 89%, respectively.
Take Home Pearls: AAC appears to be a predictor of obstructive coronary disease and all-cause mortality. The absence of AAC also appears to be a predictor of no obstructive coronary disease. Findings must be confirmed in larger groups, including lower-risk patients, before AAC can be adopted as a method of risk stratification.
For more information on the annual scientific sessions news emerging from the ACC, as well as further data on the studies presented in this feature story, go to www.acc.org.