Left ventriculography was performed in most coronary angiography cases and often when an alternative imaging modality had been recently completed, and thus, new clinical practice guidelines should be considered to decrease the overuse of this invasive test, according a study published online March 30 in the American Heart Journal.
Approximately 50 years ago, left ventriculography provided the first image of left ventricular function. Historically, it was performed as part of coronary angiography despite a small but significant risk of complications.
“Because modern noninvasive imaging techniques are more accurate and carry smaller risks, the routine use of left ventriculography is of questionable utility," wrote the study authors, who sought to analyze the frequency that left ventriculography was performed during coronary angiography in patients with and without a recent alternative assessment of left ventricular function.
Ronald M. Witteles, MD, co-director of the Stanford Amyloid Center at Stanford University School of Medicine in Palo Alto, Calif., and colleagues performed a retrospective analysis of insurance claims data from the Aetna healthcare benefits database, including all adults who underwent coronary angiography in 2007. They established the primary endpoint of the study was the concomitant use of left ventriculography during coronary angiography.
Of 96,235 patients who underwent coronary angiography, left ventriculography was performed 81.8 percent of the time—a “surprisingly high rate,” Witteles said in a statement. The use of left ventriculography was high in all subgroups, with greatest use in younger patients, those with a diagnosis of coronary disease and those in the Southern part of the U.S.
In the population who had undergone a very recent ejection fraction assessment by another modality (within 30 days) and who had had no intervening diagnosis of new heart failure, MI, hypotension or shock (37,149 patients), the researchers found that left ventriculography was performed 88 percent of the time—a rate higher than in the overall cohort.
The researchers said that in addition to the added costs (approximately $300), there are medical risks of performing this unnecessary procedure. For left ventriculography, this can include side effects from injecting contrast dye (which can be particularly harmful for patients with kidney dysfunction or diabetes), increased radiation exposure and an increased risk of abnormal heart rhythms and stroke.
“If a patient recently had an echocardiogram or a nuclear study, it didn't make them less likely to have the left ventriculography procedure—it made them more likely. That is impossible to explain from a medical justification standpoint,” Witteles said in a statement. “It is extremely unusual, in these types of cases, to need another assessment. The only logical conclusion is that a practice pattern is being defined in which tests beget more tests, whether they're necessary or not. It would be bad enough if the figure stayed at 81 percent, but our findings showed that it went up.
“The biggest downside is that the catheter goes across the valve into the heart,” Witteles said. “There's always a risk of dislodging a blood clot, causing a stroke. The procedure only takes five minutes, but it increases the risk of arrhythmias. And then there is the added cost. But the real big picture issue is how often an unnecessary, invasive test is being routinely ordered.”