WEDNESDAY, Aug. 27 (HealthDay News) -- A new scoring system for assessing patients' risk of in-hospital death after angioplasty has been confirmed to be effective, according to Mayo Clinic researchers who developed the system.

The Mayo Clinic Risk Score (MCRS) uses seven simple clinical and non-invasive variables to predict in-hospital death for percutaneous coronary intervention (PCI), the most widely performed heart revascularization process in the United States.

In 2005, doctors in the United States did more than 1.3 million PCIs, in which blocked arteries are cleared with a tiny balloon and propped open with a stent.

The Mayo researchers assessed the effectiveness of the MCRS by using it to review data on 309,351 patients who had PCI between 2004 and 2006. Their analysis indicated that the MCRS provided "excellent" predictions overall and in specific groups of patients categorized by age, gender, diabetes, renal failure, low ejection fraction and multi-vessel disease.

The researchers found that 97 percent of patients had a MCRS below 10, indicating low to intermediate risk. The MCRS initially slightly under-predicted rates of adverse events, but that problem was corrected after the system was recalibrated.

"Seven variables can be combined into a convenient risk scoring system before coronary angiography is performed to predict in-hospital mortality following PCI," the researchers wrote. "This model may be useful in providing patients with individualized, evidence-based estimates of procedural risk as part of the informed consent process before PCI."

The study was published Aug. 27 in the inaugural issue of the journal Circulation: Cardiovascular Interventions.

More information

The U.S. National Heart, Lung, and Blood Institute has more about angioplasty.