May 16, 2011

Predicting Mortality in Angioplasty Patients

(Ivanhoe Newswire) -- Novel research illustrates that elevated levels of cardiac troponin T (cTnT) or I (cTnI) in patients who had angioplasty indicate a higher risk of all-cause mortality in addition to long-term harmful events such as heart attack.  Routine monitoring of these protein levels subsequent to nonemergent percutaneous coronary intervention (PCI) might improve long-term outcomes for these patients.

According to the National Heart, Lung and Blood Institute, more than one million Americans go through coronary angioplasty each year to improve blood flow in blocked or narrowed arteries leading to the heart.  In cases where elective PCI was performed medical evidence has established that up to 30 percent of these patients encounter slight elevations in cardiac enzymes, predominantly levels of creatine kinase muscle-brain (CK-MB), which are in due course associated with an increase in in-hospital adverse cardiac events.  Greater elevations of CK-MB are associated with greater long-term mortality.

Current studies recommend that elevated levels of cardiac troponins T or I are more precise indicators of cardiac muscle damage than CK-MB.  On the other hand, contradictory data has been published in medical literature a propos the association between cardiac troponin elevation post-PCI and adverse cardiac events.  In the existing meta-analysis, Dmitriy Feldman, MD, FSCAI, and colleagues from New York Presbyterian Hospital and Weill Cornell Medical College, evaluated the pervasiveness in addition to mortality risk associated with elevated levels of cTnT or cTnI following elective PCI.

The research team conducted electronic as well as manual searches of all published studies reporting on the prognostic impact of cTnT or cTnI elevation following elective angioplasty.  Twenty-two studies, published between 1998 and 2009, were identified and included 22,353 patients.  A meta-analysis "” the largest to date "” of study findings illustrated that post-PCI levels of cTnT or cTnI were elevated in 26 percent and 34 percent of patients, correspondingly.  The follow-up period of participants in the studies examined ranged from 3 to 67 months.

"Our analysis demonstrates that post-procedural elevation of cTnT or cTnI provides long-term prognostic information regarding mortality or myocardial infarction," concludes Dr. Feldman.  Results confirm that long-term all-cause mortality in patients with elevated cardiac troponin levels after PCI was 5.8 percent in comparison to merely 4.4 percent in patients who did not experience an elevation in the cardiac enzymes.  Adverse events (death or heart attack) subsequent to elective angioplasty were considerably higher in patients with elevated cTnT or cTnI levels (9.2 percent) compared to those without cTn elevations (5.3 percent).

"Routine monitoring of peri-procedural cTn levels and more intensive outpatient monitoring and treatment of patients with cTn elevations following elective PCI may help to improve long-term adverse outcomes in these patients," Feldman advised.

SOURCE: Catheterization and Cardiovascular Interventions.  May 12, 2011.