Then and Now: Key Ways Cardiovascular Care Has Evolved Over the Past 25 Years

The 2019-20 “Best Hospitals” rankings from U.S. News & World Report mark the 25th straight year that Cleveland Clinic has been recognized as having the nation’s No. 1 program in cardiology and heart surgery.

Consult QD commemorates this milestone by looking back at the past quarter century and some of the advances and controversies that have made this a noteworthy period in cardiovascular care.

“The most striking change over the past 25 years has been the broadening of minimally invasive techniques,” says Lars Svensson, MD, PhD, Chair of Cleveland Clinic’s Sydell and Arnold Miller Family Heart & Vascular Institute. “These have greatly expanded our ability to care for the frail and elderly, shortened hospital stays and reduced the need for open large-incision surgery for a wide range of conditions. They have also improved patients’ satisfaction and ability to return to their previous lifestyle.”

Dr. Svensson noted four areas where the counterpoint between open and minimally invasive treatments has been especially dynamic: revascularization for coronary artery disease, aortic valve replacement, repair of aortic aneurysms, and electrophysiology and pacing. We take a look at how these fields have evolved over the past 25 years and where they are likely headed.

CABG and PCI for coronary artery disease

Over the past quarter century, coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) have solidified their status as the twin pillars of coronary care.

Both CABG and PCI have deep roots at Cleveland Clinic, beginning with the first use of selective cine-coronary angiography by F. Mason Sones, MD, in 1958. Dr. Sones’ work made it possible for Cleveland Clinic’s René Favaloro, MD, to successfully pioneer coronary artery bypass in 1967, and that same work led to the development of PCI in Switzerland a decade later.

Continuing CABG refinements. After Dr. Favaloro’s pioneering operations, CABG soon became one of the most-performed major surgeries in the world. “Medicare was launched around the same time as CABG,” notes Dr. Svensson. “It covered the cost of treatment for older people with coronary artery disease, and this resulted in an explosion of CABG procedures. Cleveland Clinic’s heart program was a major beneficiary, as were hospitals nationwide.”

CABG was studied and refined at Cleveland Clinic in subsequent years. A team led by Floyd Loop, MD, and Bruce Lytle, MD, established the superiority of the internal thoracic artery (ITA) to the saphenous vein graft in the mid-1980s.

“Suturing the left ITA directly to the left anterior descending artery using magnifying loops was popularized and proven beneficial at Cleveland Clinic,” says cardiac surgeon Faisal Bakaeen, MD. “This later became the cornerstone of coronary revascularizations.”

Over time, it became clear that bilateral arterial grafting was better for most patients, using either a second ITA or a radial artery graft as the second conduit. This became the recommendation of the Society of Thoracic Surgeons (STS) and others.

Dr. Bakaeen is co-author of 2016 STS guidelines that recommend arterial grafting, including bilateral thoracic grafting using a second ITA graft or a radial graft. “You have to tailor the operation to the patient,” he explains. “Bilateral ITA grafting may not be possible, or will be less attractive, in complex and high-risk patients or in those undergoing reoperation. But for a typical patient who is young, otherwise healthy and undergoing elective CABG, we believe bilateral ITA grafting is the ideal goal.”

Drs. Svensson, Bakaeen and others believe CABG should become a subspecialty of cardiac surgery, allowing more surgeons to acquire the experience and confidence needed to routinely adopt the bilateral ITA and arterial grafting approach.

Pursuing more-perfect PCI. In 1995, the first year it ranked as the nation’s No. 1 heart program, Cleveland Clinic performed approximately 2,000 CABG operations. That number dropped progressively thereafter. An important reason was the increasing use of PCI.

Stephen Ellis, MD, who served as Cleveland Clinic’s head of interventional cardiology for many years, trained with Andreas Gruentzig, MD, who developed balloon angioplasty in Switzerland in the late 1970s. He has seen the effectiveness of PCI improve over time with the introduction of bare-metal stents in the 1990s and even further in the following decade with the use of drug-eluting stents, which reduced the risk of repeat PCI.

Dr. Ellis led a recent multicenter trial of what promised to be the next major advance in PCI — bioresorbable stents. The short-term results were not favorable for the device being studied due to the risk of thrombosis. Despite the potential for long-term benefits, the device was taken off the market.

Not all the breakthroughs of the past quarter century involved devices and technology. Process improvement initiatives and related efforts focused on enhancing quality in catheterization labs and cardiac operating rooms have resulted in big gains in efficiency and outcomes, even with fewer personnel and lower cost.

For example, Cleveland Clinic’s average ECG-to-balloon time for ST elevation myocardial infarction is now well below 60 minutes, far better than the guideline-recommended 90 minutes.

“More and more cardiovascular care will be reimbursed through models like bundled payments that emphasize quality over quantity,” says Samir Kapadia, MD, Director of Cleveland Clinic’s Sones Cardiac Catheterization Laboratories and Chair of Cardiovascular Medicine. “That makes effective and efficient use of resources a paramount consideration for all institutions, and it’s what we’ve aimed to do with our cath lab process improvements.”

CABG vs. PCI. Both CABG and PCI have made big strides in early and late outcomes, but which is better for the patient? It might be generally said that, in the short term, PCI is less invasive and provides quicker angina relief and faster return to normal activities. In the long term, however, CABG may be better for enduring symptom relief and reduced risk of death or myocardial infarction, especially in patients with complex disease and a high atherosclerotic burden.

While CABG procedures dipped to 13% of Cleveland Clinic’s overall cardiac surgery volume a few years ago, today the volume has risen to 18% as patient selection has improved and it has become clear that diabetic patients fare better with CABG.

“As CABG and PCI continue to evolve, care is becoming more sophisticated with greater use of arterial conduits, less-invasive techniques, hybrid procedures and new types of stents for PCI,” observes Dr. Bakaeen. “But that won’t stop the debate over which approach is best. Coronary disease management is a collaborative heart care team effort that aims to individualize patient recommendations. The important question will always be: Which therapy is best for the individual patient based on disease burden, complexity and comorbid disease?”

SAVR and TAVR

The latest innovations in aortic valve replacement call for precisely that kind of collaborative heart team approach, building on the experience of coronary disease care teams.

Surgical aortic valve replacement (SAVR) was one of the great medical advances of the 20th century, first using simple ball valves in the 1960s and progressing to tilting disc valves in the 1970s and then biological valves in the 1980s.

Transcatheter aortic valve replacement (TAVR) was developed by French interventional cardiologist Alain Cribier in the early 2000s as a minimally invasive alternative for replacement of stenotic aortic valves, based on research by the Danish physician H.R. Andersen.

In 2011, Dr. Svensson — with a team that included Dr. Kapadia and E. Murat Tuzcu, MD, now Chair of Cardiovascular Medicine at Cleveland Clinic Abu Dhabi — performed one of the first FDA-approved TAVR procedures in America, helping set the stage for subsequent broad adoption of the technique. In fact, Cleveland Clinic performed 487 TAVR procedures in 2018, with 0.4% in-hospital mortality.

In 2007, Dr. Svensson and colleagues launched the first of a series of numbered trials called PARTNER that showed a general equivalence in outcomes between SAVR and TAVR and a superiority of TAVR over medical management (with a higher risk of stroke).

PARTNER 3, the most recent trial, concluded that “among patients with severe aortic stenosis who were at low surgical risk, the rate of the composite of death, stroke, or rehospitalization at one year was significantly lower with TAVR than with surgery.”

But Drs. Svensson and Kapadia note that for all its comprehensiveness, PARTNER 3 had many exclusions, as well as subtle differences between its treatment groups, such as a higher rate of concomitant procedures like CABG in the SAVR group (26%) compared with the TAVR group (8%). And the recently released results were only for one year, with follow-up scheduled to continue for 10 years to assess the durability of TAVR devices. “Unless there are extenuating circumstances, like radiation heart disease or dialysis, patients younger than 65 generally should not have TAVR at this point,” Dr. Svensson observes.

Open and endovascular aneurysm repair

When Cleveland Clinic was first ranked No. 1 in 1995, open surgery was the gold standard for abdominal and thoracoabdominal aortic aneurysms. Today, Cleveland Clinic has among the nation’s most experience and lowest mortality for these often-challenging open procedures. “Our program’s vast experience has enabled consistent achievement of less than 1% mortality with open first-time abdominal aortic aneurysm surgery,” notes Vascular Surgery Chair Sean Lyden, MD.

However, the open thoracoabdominal operation comes with many potential complications, including paraplegia, and requires a long recovery period. The search for a less-invasive alternative to open thoracoabdominal aneurysm repair began with vascular surgeon Juan Parodi, MD, a trainee at Cleveland Clinic in the mid-1970s. In his last year at Cleveland Clinic, Dr. Parodi began contemplating an intravascular approach to aneurysm repair. He worked on the problem after returning to his native Argentina in 1979, and in 1990 he performed the first successful endovascular abdominal aneurysm repair (EVAR) in Buenos Aires.

Over the past quarter century, the devices for endovascular repair have grown steadily more sophisticated. Today’s stent grafts are fabric tubes supported by a wire scaffold, which are guided to the aneurysm site and deployed in the diseased aorta segment. The stent relines the aorta like a sleeve.

The evolution of EVAR in the early 2000s was promoted at Cleveland Clinic by the late Roy Greenberg, MD, a vascular surgeon who helped develop branched and fenestrated grafts. Cleveland Clinic has led the world in treatment of thoracoabdominal aneurysms with endovascular devices and has shown the outcomes in high-risk patients to be better than those with open surgery in healthy patients. Cleveland Clinic continues to be involved in clinical trials designed to lead to commercialization of this technology in the U.S.

“Today, about 80% of abdominal aneurysms are treated with stent grafts,” notes Heart & Vascular Institute Chair Dr. Svensson. “We hope that in the future we will be able to treat as many thoracoabdominal aneurysms with this minimally invasive approach.”

“Expanding indications for endovascular procedures are changing the equation, increasingly giving high-risk patients a chance to receive lifesaving therapy, including in cases of arch aneurysms,” says Eric Roselli, MD, Surgical Director of Cleveland Clinic’s Aorta Center. He and his colleagues foresee increasing collaboration among cardiac and vascular surgeons on hybrid procedures, where the area near the aortic valve is operated on through an open incision while vessels lower in the body receive endograft repair.

Electrophysiology and pacing

The treatment of heart rhythm disorders has evolved in several directions since 1958, when Earl Bakken built the first pacemaker at the University of Minnesota.

Today, Cleveland Clinic’s Section of Electrophysiology and Pacing, headed by Oussama Wazni, MD, offers a wide variety of highly specialized approaches. These include the newest implantable cardioverter-defibrillators (ICDs), biventricular pacemakers, leadless pacemakers, sophisticated remote monitoring devices, genetic testing, medical management and follow-up, lead extraction, and advanced mapping and ablation therapies.

By the mid-1990s, patients with heart rhythm disorders were able to benefit from almost three decades of innovation — from lithium battery pacemakers to dual-chamber pacemakers to steroid-eluting leads. Microprocessors were making pacemakers reactive to patient activity levels for the first time. All raised pacemaker therapy to new levels of safety and effectiveness.

Around the same time, transcatheter radiofrequency ablation (RFA) was becoming an effective alternative to open heart operations for treating paroxysmal atrial fibrillation — owing much to the improvements in electrophysiological testing and mapping taking place at the time.

Electrophysiologist Bruce Lindsay, MD, who retired from Cleveland Clinic this year, remembers that era well: “The early days of ablation were not easy because we were on the forefront and there was nobody to teach us. We figured it out based on our understanding of physiology.”

In fact, “nobody wanted to talk about atrial fibrillation before RFA,” Dr. Lindsay says. “There was not much we could do to help patients apart from cut-and-sew so-called maze procedures. Ablation procedures have changed the landscape, and they are now the foremost topic at scientific sessions.” Open-chest maze operations are still done in combination with other cardiac surgeries or as a stand-alone operation in selected patients.

Dr. Svensson points out that in the 1980s ablation procedures for ventricular tachycardia or fibrillation were done by excising scar tissue or freezing the scar. “Now this is frequently treated by defibrillation and occasionally by ablation,” he says.

Dr. Lindsay was among those who helped demonstrate the feasibility of transvenous cardioversion and defibrillation in the mid-1980s. “Patients used to spend weeks in the hospital and undergo repeated electrophysiology studies to identify drugs that might prevent life-threatening ventricular arrhythmias,” he says. “With the advent of ICD therapy, we simply implanted an ICD and sent the patient home within a week.”

Lead management, including extraction, is another area where Cleveland Clinic has helped chart new territory since the 1990s. “We help patients plan for lifelong therapy with pacemakers and defibrillators with leads,” explains Bruce Wilkoff, MD, Director of Cardiac Pacing and Tachyarrhythmia Devices. “We continue to work on reducing the need for lead extraction while improving the safety of doing so if it’s necessary.”

While Cleveland Clinic cardiologists have helped lead several recent trials of leadless devices, such devices don’t meet the needs of all patients. “Leads are going to be around for a long time to come,” Dr. Wilkoff predicts.

Meanwhile, surgical treatment for arrhythmias has been progressing on a parallel track during this period with better lesion sets and ablation methods. Refinements of the maze procedure introduced in 1992 made it a gold standard for treatment of atrial fibrillation.

Cleveland Clinic performed the first operation combining the maze procedure and CABG. A. Marc Gillinov, MD, Chair of Thoracic and Cardiovascular Surgery, says that nearly all patients with preexisting atrial fibrillation who undergo heart surgery should have an ablation or maze done at the same time.

“The addition of an ablation or maze does not increase risk,” he says. “The maze works in most people, and it includes excision or exclusion of the left atrial appendage, which is a primary source of stroke and other thromboembolic events.”

Next 25 years?

The next 25 years will undoubtedly see advances in robotic surgery, off-pump surgery, stents for the treatment of peripheral arterial blockages and continued refinement of therapies for dyslipidemia. Insights emerging from Cleveland Clinic laboratories are pinpointing the roles of the gut microbiome in development of various forms of heart disease. Surgeons and interventional cardiologists will be able to treat patients who are older and sicker than ever before, with technologies enhanced by big data, deep learning and artificial intelligence techniques. Cardiac CT and MRI will combine with virtual reality to create unique 3D imaging environments.

“We are proud to be No. 1,” says Dr. Svensson, “but we are never satisfied. Our goal is continual improvement of quality, safety and outcomes. We are grateful for the support of our colleagues worldwide, and are honored to play a role in this great international effort to heal the diseases of the heart and give everyone the best chance at a long, productive, happy and healthy life. Our mantra is to innovate change, improve practice and ensure untouchable high-quality outcomes and value for our patients.”