Novel risk score estimated 30-day mortality for PCI

A novel risk score may allow clinicians to estimate in-hospital and 30-day mortality for coronary stenting procedures quickly and accurately, according to new research.

The PCI risk score also performed reasonably well as a predictor of complications and length of stay.

For the study, researchers used data from 54,223 patients in New York’s Percutaneous Coronary Interventions Reporting System, which was used to develop a logistic regression model for patients who underwent PCI in 2010, which was converted into a simple linear risk score that estimated mortality rates. Researchers then validated the score by applying it to 2009 New York PCI data and evaluated the ability of the score to predict complications and length of stay.

Eleven risk factors comprise the score, with individual components ranging from 1 to 9, and the highest total score seen in the study of 34 (43 hypothetical). The factors include: age, female gender, unstable hemodynamic state, shock, ejection fraction, preprocedural MI (with ST-segment elevation in hours, without ST-segment elevation in hours and with or without ST-segment elevation in days), comorbidities, renal failure and vessel disease. The risk factors with the largest influence are shock (9 points) and STEMI 12 to 23 hours before admission.

Three risk factors are new to this score: malignant ventricular arrhythmia, chronic obstructive pulmonary disease and two/three vessel disease.

According to the researchers, more than 90% of the patients undergoing PCI had a risk score of 9 or less, and more than 70% had a score of 5 or less, with a predicted short-term mortality of <0.5%, leading them to conclude that for a large proportion of patients, the short-term mortality risk is not a deterrent in choosing PCI in lieu of a competing intervention.

Lloyd W. Klein

In an accompanying editorial, Lloyd W. Klein, MD, and Justin Maroney, MD, of the Advocate Illinois Masonic Medical Center and Rush Medical College, Chicago, wrote that risk scores have not garnered more widespread use despite their ease of use because they do not answer the questions most important to patients: health status and quality of life.

“The challenge for future PCI risk models is to overcome the limitations imposed by the existing structure of the registries from which they are derived and become more accessible for real-time clinical decision-making,” they wrote. “To accomplish this transformation, they must be modified to integrate factors and outcomes that will more effectively guide physicians and patients.”

Responding to the editorial, Edward L. Hannan, PhD, study investigator with the University of Albany, State University of New York, told Cardiology Today’s Intervention that he agreed that incorporating other outcome measures would be helpful, particularly for patients with stable CAD, for whom the short-term risk is low. “In that regard, we have a long-term risk score under review right now that can be used in conjunction with the short-term risk score for purposes of comparing PCI and CABG,” he said.

Edward L. Hannan

In terms of there being other reasons for mortality after discharge within 30 days after the procedure, Hannan said is important for patients to be aware of this 30-day risk even if death cannot be directly attributed to the procedure.

“The models are not created for purposes of assessing appropriateness, and this is something that can be done by clinicians prior to use of the models using American College of Cardiology criteria,” he said. “Information on short- and long-term mortality for PCI and CABG will soon be available using New York risk scores so that outcomes for patients who are appropriate for both procedures can be evaluated more extensively as a function of their specific risk factors, many of which are not included in appropriateness criteria.”

For more information:

Hannan E. J Am Coll Cardiol Intv. 2013;6:614-622.

Klein L. J Am Coll Cardiol Intv. 2013;6:623-624.

Disclosure: Hannan, Klein and Maroney report no relevant financial disclosures.