乌鸦传媒

Gross overestimation of stenosis severity by visual assessment has found its way into clinical practice in China, where the oculostenotic reflex may be even worse than in the U.S., a retrospective study suggested.

Among recipients of percutaneous coronary intervention (PCI) in China who did not have acute MI, mean percent diameter stenosis was 87.7% when estimated visually and 71.7% with core lab-derived quantitative coronary angiography (QCA), an (P<0.001). People with acute MI had a similar tendency to have stenoses overestimated this way (93.7% versus 83.6%, P<0.001).

Half of lesions said to have crossed the 70% stenosis threshold actually turned out to be less severe by QCA in patients without acute MI; this was similar but less pronounced in the case of acute MI patients, according to Lixin Jiang, MD, PhD, of China's Fuwai Hospital, and colleagues in their report published online in JAMA Internal Medicine.

Across the hospitals included in the study, visual overestimation of stenosis severity ranged 7.6% to 21.3% for non-acute MI and 5.4% to 20.0% for acute MI. Individual physicians differed from QCA results by a range of 6.9% to 26.4% and 0.6% to 26.9%, respectively.

A similar study from 2013 found that the absolute difference between visually- and QCA-estimated stenosis severity was 8% in the U.S., half what is currently being reported for non-acute MI cases from China.

"Large variations across hospitals and among physicians suggest that efforts are urgently needed to improve the accuracy of interpretations of coronary angiograms and to optimize the selection of patients for PCI in current clinical practice," Jiang's group concluded.

"Despite being challenged as long as 40 years ago, owing to its convenience, efficiency, and ease of implementation, visual assessment is still the main method used to determine percent diameter stenosis in China and other countries. Given that the clinical standard, physician visual assessment, frequently resulted in an overestimate of lesion severity compared with the less subjective QCA, it is possible that revascularization would not have been pursued in some lesions -- an implication that is similar to findings from the United States."

"This carefully performed analysis from the China PEACE study adds to the concern of overuse of PCI," according to an editor's note from Rita Redberg, MD, MSc, of the University of California San Francisco. "Visual assessments tend to systematically overestimate the magnitude of the stenosis, meaning that patients will get an intervention on a lesion that is not hemodynamically significant."

Jiang and colleagues looked at a random 1,295-person subset of the China PEACE Prospective PCI Study. Participants had gotten PCI at 35 hospitals. Coronary angiograms were sent to two independent core laboratories for review by QCA.

Things may be even worse than they seem, the investigators said: Participating sites constituted a group of tertiary care hospitals, so the degree of misinterpretation could have been even worse if other Chinese hospitals were included.

"As has been amply documented, the oculostenotic reflex takes over in the catheterization laboratory. This enthusiasm for use of PCI, whether motivated by our love for technology, feeling like we are doing something when we open a stenosis, or related to our fee-for-service healthcare system, is hard to resist once a patient reaches the catheterization laboratory," Redberg wrote.

"The best approach is not to refer these stable patients to the catheterization laboratory in the first place, but rather to start medical therapy and follow the patient clinically."