Many PCI Patients Treated in China Have No Angina Symptoms
Amid the rapid uptake of PCI in China, more attention should be paid to patient selection to boost the quality-of-life benefit, researchers say.
As China’s use of percutaneous coronary intervention continues its explosive growth, there are signs that the treatment is not being targeted at the right patients. One in seven people who undergo PCI for unstable angina report having no recent symptoms, as do one in four being treated for stable CAD, according to new data out of China.
The analysis, published last week in JAMA Network Open, stems from the China PEACE study, which tracked more than 1,600 consecutive patients who had elective PCI for indications other than acute MI at 40 hospitals spread across 18 Chinese provinces between December 2012 and August 2014.
This is a mere slice of China’s overall PCI volume. Lead investigator Yuan Lu, ScD (Yale University/Yale-New Haven Hospital, CT), and colleagues point out that “more than 300,000 procedures were performed in 2011, an 18-fold increase compared with 2001.”
Beyond a rapid growth in PCI, another notable feature about China is that it’s home to some of the largest PCI centers in the world, Gary S. Mintz, MD (Cardiovascular Research Foundation, New York, NY), told TCTMD. “There’s tremendous expertise in China, but there’s also tremendous heterogeneity,” with the biggest centers and volumes “clustered in the largest cities, particularly in the eastern part of the country,” he said.
“The question is: how do people get to a PCI when they’re asymptomatic? They’re mostly talking about stable patients undergoing PCI without symptoms,” Mintz observed, adding that it’s unclear why these patients are being selected for treatment. One possibility, he said, is that they undergo diagnostic angiography because they exhibit other symptoms like shortness of breath or heart failure that hint at silent ischemia.
Lu agreed, telling TCTMD: “We think there are several reasons that could explain this finding. First of all, there may be other symptoms, atypical symptoms reflecting angina equivalents that are present, so the clinician thinks it may be useful to use this procedure. . . . Also, there [may be] other reasons—for example, in China there are some financial gains by the clinician if they recommend further diagnosis and testing.” Finally, ischemia may have been revealed by other means of noninvasive testing, she added.
The fact that so many patients had PCI but minimal or no symptoms, though, “raises the concern of whether it’s appropriate to do such invasive procedures on these patients,” Lu stressed.
Worse Symptoms Precede More Benefit
Among the 1,611 included patients, one-third were women and the mean age was 61.3 years. Indications were stable CAD for 27.5% of the cohort and unstable angina for 72.5%. Most had CV risk factors such as hypertension (68.5%), dyslipidemia (50.8%), and diabetes (29.1%). More than one-third were smokers. Histories of MI and stroke were uncommon at 16.1% and 14.1%, respectively, though 34.8% had a history of heart failure.
Both Lu and Mintz pointed out that, unlike in the United States, the majority of China’s PCI patients present with ACS rather than stable disease.
Responses to the Seattle Angina Questionnaire (SAQ) indicated that 25.7% of patients with stable CAD and 15.0% of those with unstable angina had no angina symptoms in the 4 weeks prior to PCI, though 74.3% of those with stable CAD and 85.0% of those with unstable angina said they had some degree of chronic symptoms. Patients who reported chronic symptoms tended to be older and female.
Overall, 18% of the cohort had minimal angina symptoms (SAQ Angina Frequency Score ≥ 90), which means these individuals had “no potential for substantial clinical improvement,” the researchers note.
Fully 89.8% of PCIs were done through radial access. In-hospital complication rates were low for ischemic stroke (3.6%), bleeding (3.5%), recurrent MI (1.4%), and atrial fibrillation or flutter (1.2%). Mean length of stay was 11.2 days.
By 1 year after PCI, there was “considerable heterogeneity” in how patients fared, Lu et al note, though most reported their quality of life was excellent (48.2%) or good (39.5%). For 32.5%, the SAQ Quality-of-Life score had improved by at least 10 points. Patients with worse angina at baseline tended to have greater clinical gains.
Characterizing which people stand to gain the most is “particularly important in developing countries such as China, where there are relatively fewer medical resources and not enough interventional cardiologists to perform these procedures. Identifying patients who are not likely to benefit from PCI averts waste in the health system and the potential risks associated with the procedure,” the investigators write.
Asked about the utility of the SAQ, Mintz described it as a “useful tool for studying groups of patients to identify their level of symptomatology,” but not so much as a tool for clinical decision-making.
Lu, on the other hand, suggested that the SAQ could, in fact, be useful in making day-to-day decisions.
“The most important message is for the clinician to ascertain the angina symptoms of patients prior to the procedure. The tools, the methods are there. It takes very little time, 10 to 15 minutes, to go through the questionnaire,” she advised. “That will avoid unnecessary procedures and also give a better sense for patients of their benefits and risks with the PCI procedure.”
Lu Y, Zhang H, Wang Y, et al. Percutaneous coronary intervention in patients without acute myocardial infarction in China: results from the China PEACE Prospective Study of Percutaneous Coronary Intervention. JAMA Network Open. 2018;1(8):e185446.
- Lu and Mintz report no relevant conflicts of interest.