Coronary CTA identified CAD mortality risk in patients

Min J. J Am Coll Cardiol. 2011;58:849-860.

Issue: September 2011

Coronary CTA successfully identified those at heightened risk for all-cause mortality, providing worsened prognosis for patients with obstructive or nonobstructive coronary artery disease, according to a study.

The researchers evaluated 24,775 patients aged at least 18 years from 12 centers using Coronary CT Angiography Evaluation for Clinical Outcomes: An International Multicenter Registry (CONFIRM) data gathered between 2005 and 2009 who underwent at least 64-detector row coronary CTA for suspected CAD. CAD severity was judged on a per-patient, per-vessel and per-segment basis, and the severity was defined as either none (0% stenosis), mild (1%-49% stenosis), moderate (50%-69% stenosis) or severe (≥70% stenosis). Patients with known CAD or a history of MI, coronary revascularizations and cardiac transplant were excluded from the study.

The coronary CTA scans were performed on a variety of different scanner platforms, and then analyzed by level 3-equivalent cardiologists who had experience interpreting several thousand coronary CTA scans. Any uninterpretable coronary artery segment that was scanned was scored similarly to the most proximal segment that was evaluable, according to researchers. Time to mortality was then estimated using multivariable Cox proportional hazards models.

A follow-up was obtained for 96.3% of patients. Researchers recorded 404 deaths in the follow-up, and an increasing severity of CAD in men, patients with diabetes, hypertension, dyslipidemia, family history of CAD, who currently smoke, typical angina, and high pre-test likelihood of CAD. Patients who had died before follow-up “had significantly more severe coronary artery stenosis in the majority of coronary segments” compared with patients who were alive at follow-up. Only 0.65% of deaths occurred in patients without evident CAD.

“The study cohort was middle-aged with a high prevalence of CV risk factors and symptoms,” researchers wrote. “They presented with typical or atypical angina in the majority of cases, with the majority of individuals having intermediate or high pre-test likelihood of obstructive CAD.”

Overall, both obstructive and nonobstructive CAD presented increased risk for mortality compared with patients without evident CAD, according to researchers. Patients with nonobstructive, obstructive one-vessel, two-vessel, or three-vessel or left main CAD had an increased risk of mortality, with two-vessel and three-vessel showing higher hazards for death in younger patients, and three-vessel CAD showing higher hazards for women compared with men.

“These results of the CONFIRM registry represent the first prospective international multicenter data to relate [coronary] CTA-determined extent and severity of CAD to all-cause mortality and demonstrate the independent prognostic value of both obstructive as well as nonobstructive CAD by [coronary]CTA,” the researchers wrote.

Disclosure: The researchers report no relevant financial disclosures.

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