A study published in JAMA Network Open August 11 suggests that, despite the growing use of imaging modalities like computed tomography and MRI, echocardiography remains the most popular method for imaging patients with heart failure (HF).
Resting echocardiography has been a mainstay of CV imaging since its introduction in the early 1950s, but, as Juarez R. Braga, MD, and colleagues wrote in JAMA, its efficacy has been called into question as newer therapies like PET, invasive coronary angiography and myocardial perfusion scintigraphy have made their way onto the cardiology scene. Still, echos remain a major component of HF management.
“Although echocardiography is still the foundational imaging technique in the investigation of HF, the armamentarium of diagnostic tools has expanded in recent years,” Braga, of the University of Toronto, and co-authors said. “Access to other cardiac imaging modalities is now considered essential because of their utility in identifying underlying causes, risk stratification and selection of therapies.”
Braga et al. conducted a repeated cross-sectional study of 882,355 Canadian adults with prevalent HF between April 2002 and March 2017, noting the use and cost of the cardiac imaging modalities used to treat those patients. The age- and sex-standardized prevalence of heart failure itself remained stagnant during the study, ranging from 2.4% in 2002 to 2% in 2016.
The usage of resting echo increased over the study period, the authors reported, from 386 tests per 1,000 patients with HF in 2002 to 533 tests per 1,000 patients in 2011. Rates dropped immediately after Canada introduced an accreditation program for echocardiography in 2012, dropping by an average of 59.5 tests per 1,000 patients before reaching a plateau in subsequent years.
A concomitant 10.8% relative reduction in the use of myocardial perfusion scintigraphy and 11.2% reduction in the use of invasive coronary angiography between 2011 and 2016 accompanied the plunge in echocardiography usage, but echos still accounted for the most tests and greatest costs during the study.
Braga and colleagues said the decrease in the rate of growth of echocardiography also coincided with the rise of other imaging modalities, including cardiac MRI and CT, in the 2010s.
“The findings by Braga et al. mirror the rapid increase and decrease in the rate of growth of diagnostic cardiovascular imaging in the United States, and available evidence suggests that this trajectory occurred as a result of a complex interplay between patients, clinicians, payers and healthcare systems,” Vinay Kini, MD, of the University of Colorado Anschutz Medical Campus, wrote in a linked editorial. “Descriptive studies of imaging trends such as the one by Braga et al. provide important information on real-world changes in the use of cardiac imaging services and costs.”
Kini said studies like Braga and colleagues’ are still limited by the fact that they typically don’t account for whether imaging was beneficial to patients and they’re generally unable to establish causal connections to factors that may have affected modality use, and wrote that future studies should consider using additional methods of observational data analysis.
“These methods might include exploring the sequence and progression of testing, understanding trends in certain high- and low-value imaging tests that can be identified from administrative data with reasonable sensitivity and specificity, or using difference-in-difference analytic models with clearly defined exposures and outcomes,” Kini wrote. “To guide future policies on the use of cardiovascular imaging, a better understanding of the causal factors affecting cardiac imaging use and the effect of changes in use on imaging quality is needed.”