Evidence-based medicine forms ‘fabric’ behind interventional cardiology

Roxana Mehran

SAN DIEGO — During the past 40 years, new technologies, treatments and techniques in interventional cardiology have faced intense scrutiny and the community has consistently responded with strong scientific evidence, according to Roxana Mehran, MD.

“Evidence-based medicine has been the fabric and cloth that we have woven and stands behind everything we do,” Mehran, who is associate medical editor of Cardiology Today’s Intervention and a cardiologist and professor of medicine at Icahn School of Medicine at Mount Sinai, said during a lecture at the Society for Cardiovascular Angiography and Interventions Scientific Sessions.

Interventional cardiology came into existence more than 40 years ago when radiologist Charles Dotter, MD, performed the first angioplasty and subsequently reported his results, showing that the procedure was possible based on the evidence of a single angiogram. This development was followed by the first coronary angioplasty, which was performed by Andreas Grüntzig, MD, who developed the balloons used in the procedure in his kitchen.

Not only did Grüntzig stand behind this new technique despite skepticism from others in the medical community, Mehran noted, but he and his colleagues evaluated patients for decades because they understood the importance of follow-up.

“They set the rules that we would not only be innovators but would report our results and stand behind our findings,” she said.

Technological innovation

After the introduction of balloon angioplasty, there were many new developments in the field that withstood close scrutiny, according to Mehran, including bare-metal stents, which were less than ideal due to high restenosis rates, and the first drug-eluting stents.

Although DES were supported by randomized clinical trials and would be recognized as a major step forward, data linking the first-generation devices to increased mortality caused a significant decline in their use.

Interventional cardiologists, however, persisted in refinement of the technology and the second- and third-generation DES with reduced strut thickness and enhanced drug delivery have greatly improved outcomes. All of this innovation, Mehran noted, would not have been possible without data from large-scale clinical trials.

This emphasis on a strong evidence base has also ensured that the interventional cardiology community does not value innovation over patient care, according to Mehran. For example, the development of a fully absorbable scaffold (Absorb, Abbott Vascular) generated considerable interest, but when negative results from trials of the device were published, it was taken off the market.

Transcatheter aortic valve replacement, however, may be the most significant development in the field, according to Mehran.

“Interventional cardiologists together with cardiac surgeons have now made the most disruptive therapy available to our patients,” she said. “The first TAVR was performed in 2002 and was done so with the highest level of scrutiny and the highest level of science that has not been matched in any other subspecialty.”

This effort continues even now, Mehran said, noting that with each complication or issue related to TAVR, clinicians and researchers are ready and eager to study the problem in clinical trials and find a solution.

Self-scrutiny

In addition to supporting the development of novel treatments, the focus that the interventional cardiology community places on robust scientific evidence forces clinicians to continually evaluate their own clinical practices, according to Mehran.

“The COURAGE trial, presented a decade ago, made us question our own practices. As a result, the society came together so we could ask ourselves: How can we do this better?” Mehran said. “We increased the scrutiny of our own procedures and determined that ischemia needed to be documented through tests, fractional flow reserve or instantaneous wave-free ratio.”

More recently, she noted, results of the sham-controlled ORBITA trial, presented at TCT 2017, stirred up controversy, leading some to criticize the use of PCI in patients with stable angina. Furthermore, media reports, negative editorials and conversations on social media engendered concern among both clinicians and patients. These data again will likely cause clinicians to reflect on their approach to care and treatment, she noted.

However, it is important to recognize the decline in CVD mortality in relation to scientific advances during the 40 years since Grüntzig performed the first coronary angioplasty, indicating that the cardiology community is moving in the right direction, Mehran said.

Future perspectives

Although innovation is not slowing down, interventional cardiology has moved past the days of a single angiogram or developing devices in the kitchen, according to Mehran.

“We are increasing the granularity of what we do,” she said, noting that the inclusion of patients from different racial and ethnic backgrounds as well as the inclusion of more women in clinical trials is important. “Additionally, we need to be more inclusive with not just the diversity of our patients but also in the disease process. We will no longer exclude patients with chronic kidney disease on permanent renal replacement or patients with high bleeding risk.”

Another paradigm shift is the movement away from hard outcomes to patient-reported outcomes in clinical trials, Mehran noted.

“These are the outcomes that matter, not the ones we care about but the ones that matter to patients,” she said.

Importantly, the future of interventional cardiology is not just limited to novel treatments and improved patient care. Increased diversity among clinicians in the subspecialty will play a major role as well.

“Female clinical trial leaders have paved the road for the next generation of women who will be able to do the same but not be made to feel inferior or uncomfortable. SCAI has set the incredible platform for women to feel comfortable and lobby for better representation of women in interventional cardiology,” Mehran said.

Finally, it is important to recognize the great strides that have been made during the last 40 years and understand that there is more work to be done, according to Mehran.

“I hope you all feel proud of what has been done to enhance the lives of patients and to note that we can always do better and will do our best until we know how to do better,” she said. – by Melissa Foster

Reference:

Mehran R. Founders’ Lecture: Evidence-Based Science Behind Interventional Cardiology: A Forty-Year Journey. Presented at: Society for Cardiovascular Angiography and Interventions Scientific Sessions; April 25-28, 2018; San Diego.

Disclosure: Mehran reports she has financial ties with multiple pharmaceutical and device companies.