The posters at the American College of Cardiology conference that were nominated for awards indicate the depth of cardiovascular research. Topics ranged from the prognostic value of troponin T levels in ambulatory patients with stable coronary artery disease (first place) to how one’s socioeconomic position predicts graft failure in pediatric heart transplant recipients.
In the top poster, Bill Pei-Chin Hsieh, MD, and colleagues at the University of California, San Francisco, sought to determine whether cardiac troponin T (cTnT) serves as an independent marker for CAD severity and future events.
They studied 988 patients with stable CAD who had plasma cTnT measurements before performing exercise treadmill testing with stress echocardiography. The 6 percent of patients who had elevated cTnT levels were significantly associated with the presence of one of the following:
- left ventricular ejection fraction < 50%
- moderate to severe diastolic dysfunction
- left ventricular end-diastolic volume ≥ 75 ml/m2, or
- baseline wall motion abnormalities.
Researchers followed patients for a mean of four years and found that those with elevated troponin T levels had significantly more cardiovascular events.
In another poster, James K. Min, MD, from Weill Cornell Medical College and colleagues from various facilities chronicled results from the first prospective multicenter study comparing 64-slice coronary CT angiography (CCTA) with quantitative coronary angiography (QCA).
The study, which enrolled 232 patients from 16 academic and private practice sites, demonstrated high accuracy of CCTA to reliably detect >50 percent and >70 percent stenosis in chest pain patients being referred for invasive coronary angiography.
The per patient sensitivities to detect stenosis >50 and >70 percent were 95 percent and 94 percent, respectively. Per vessel sensitivities were 83 percent and 85 percent, respectively. The negative predictive value across the board was 99 percent.
An important point to consider, according to Min, is that researchers did not exclude any patients based on high heart rate, high baseline calcium score or high body mass index. Additionally, they included all vessel segments in the analysis irrespective of size.
“We’ve established CCTA’s diagnostic accuracy. Now we need to prove that it’s clinically useful,” Min told Cardiovascular Business News.
That can be done in three ways, he said. First, prove it’s more cost-effective to use CCTA as a first line test. Second, demonstrate that the findings on CCTA have prognostic value. And third, conduct prospective randomized trials comparing CT with the standard of care.
In the poster that took second place, Mustafa Hassan, MD, and colleagues from the University of Florida, Gainesville, for the first time identified a genetic marker that increases a patient’s risk for developing myocardial ischemia during a psychological stress situation.
“We know from previous studies that developing myocardial ischemia during a psychological challenge confers increased risk for death and other cardiac events. So the finding of this study may help us identify patients at increased risk for these adverse effects,” Hassan told Cardiovascular Business News.
Researchers found that mental stress-induced myocardial ischemia (induced via a public speaking task) occurred three times more frequently in patients with a particular genotype (ADRB1 vs. ADRB2). In the sample of 146 patients, 73 percent were homozygous for this genotype, Hassan said.
The next step is to explore more candidate genetic markers with potential effect on the stress response and also examine the effects of these genetic markers on mortality and cardiac events, he said.
This line of inquiry can also be used to design and test therapeutic interventions to reduce stress reactivity and the occurrence of myocardial ischemia, Hassan said.