Lack of on-site cardiac surgery may not compromise PCI outcomes
medwireNews: A large US study suggests that the risk of in-hospital mortality is similar in patients undergoing percutaneous coronary intervention (PCI) at centers with and without on-site cardiac surgery (CS).
In an analysis of data from almost 7 million PCI procedures carried out over 10 years, Charanjit Rihal (Mayo Clinic, Rochester, Minnesota, USA) and colleagues found that 1.4% of 6,515,491 patients undergoing PCI at centers with onsite CS died in hospital, compared with 1.9% of 396,741 at centers without onsite CS, translating into significantly lower unadjusted mortality rates at centers with onsite CS (odds ratio [OR]=0.74).
However, after multivariate adjustment for factors including demographics, comorbidities, clinical risk factors, and prior cardiac disease, in-hospital mortality rates were not significantly different (OR=1.01), report the researchers in JAMA Cardiology.
Additionally, there was a sevenfold increase in the number of PCIs being performed at hospitals without onsite CS over the study period, from 1.8% in 2003 to 12.7% in 2012.
In an accompanying commentary, H Vernon Anderson (The University of Texas Health Science Center at Houston, USA) explains that the safety of PCI has “improved enormously” over the past 40 years, and the need for emergency coronary artery bypass grafting has “strikingly diminished”.
As a result, “the requirement that PCI should be conducted only in centers with cardiac surgery available on-site has been gradually relaxed,” he adds.
In subgroup analyses, there was no significant difference in adjusted in-hospital mortality rates between centers with and without onsite CS when PCI was carried out for different indications, including ST-elevation myocardial infarction (OR=0.99), non–ST-elevation acute coronary syndrome (OR=0.99), and elective PCI for stable ischemic heart disease (OR=0.93).
The team found a significant inverse association between procedural volume and in-hospital mortality rates in centers with and without onsite CS. Among centers without onsite CS, mortality rates were 2.2% in hospitals performing 200 or fewer PCIs annually, compared with 1.6% and 1.3% in centers with annual volumes of 201–400 and more than 400, respectively.
“These results have important clinical and policy implications because they are applicable to the general US population requiring acute interventional care,” believe the study authors.
The commentator agrees, but notes that “first, additional studies will need to be done to either confirm or refute these volume-outcome findings for the 2 types of centers.
He adds that “much more investigation is needed to determine with greater precision the volume thresholds where mortality rates and other adverse event rates decline.”
Anderson emphasizes the importance of PCI volume in individual hospitals “to keep centers above the threshold for excellent outcomes”, concluding that “[t]he precise details of PCI procedure volume balance will vary from region to region and will require time, effort, difficult thinking, and possibly some hard choices.”
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