Primary PCI should be considered as a first choice reperfusion strategy when feasible, according to a meta-analysis published in this month's American Heart Journal. Researchers found primary PCI was linked to a reduction in 30-day mortality, irrespective of a patient's baseline risk.
“Based on the results of several randomized clinical trials and meta-analyses, it is broadly accepted that the strategy of primary PCI compared with fibrinolytic therapy results in better outcomes in patients presenting with acute MI,” the authors wrote.
To better assess which patient populations would most benefit from primary PCI, Sanneke P. M. de Boer, MD, of the Erasmus Medical Center in Rotterdam, the Netherlands, and colleagues evaluated 6,763 patients enrolled in 22 randomized controlled trials for the safety and efficacy of primary PCI vs. fibrinolysis.
The researchers developed a risk score to estimate the probability of 30-day mortality in patients and then divided patients into quartiles according to that risk.
The researchers reported that 446 patients died within 30 days of randomization to a RCT. Compared with younger patients, patients over the age of 70 were 10 times more likely to die within 30 days. In addition, de Boer et al found that patients randomized to receive primary PCI (PPCI) had a lower mortality compared to patients randomized to fibrinolysis, 5.3 percent vs. 7.9 percent, respectively.
“The interaction between risk score and allocated treatment interaction term had no significant contribution (P = 0.52) to the model, indicating that the relative mortality reduction by PPCI was similar at all levels of estimated risk,” the authors wrote.
The researchers also noted that the numbers to treat to prevent a death by primary PCI compared with fibrinolysis was 516 in the lowest quartile and 17 in the highest quartile. There was a 37 percent relative risk reduction by primary PCI across each quartile.
"One of the challenges for contemporary medicine is to rationally implement available therapies in clinical practice, in the appropriate patients at the appropriate time,” the authors wrote. “Before certain therapy will be initiated, a physician must consider the probability that the patient will improve or deteriorate without such therapy, the chances of improvement if the therapy is initiated, the risks of adverse events, and, last but not least, the therapy related costs.”
The authors said that this meta-analysis offers ways to improve evidence-based treatment decisions for MI patients in “cost-conscious environments.”
“In our view, fibrinolysis remains a legitimate option for the categories of patients with estimated NNTs [number needed to treat] that exceed 100, particularly in regions where hospitals with PCI facilities are rare, or where the costs related to PPCI are considered too high to treat the entire MI population, because fibrinolysis compared with conservative treatment has proven to reduce mortality by 25 percent to 30 percent when initiated within three hours of symptom onset,” the authors wrote. However, if initiated within 12 hours, there was still a 15 percent reduction in mortality.
“If access to PCI is longer than two hours, fibrinolysis remains a legitimate option, especially for patients with a low-risk score due to the small absolute risk difference between both treatment modalities in this patient group,” the authors concluded. “Therefore, in regions where hospitals with PCI facilities are rare, respectively, where geography does not allow primary PCI in all patients with MI, this risk score might be used to select those higher risk patients who benefit most from PPCI.”