The Society for Cardiovascular Angiography and Interventions (SCAI) meeting in Orlando, FL, attracted a large US and international attendance of specialists.
Leaders of SCAI highlighted the many challenges interventional cardiologists face in today’s climate. Kenneth Rosenfield, MD, FSCAI, co-chair said, “SCAI 2013’s Opening Session will truly ignite our meeting, highlighting the successes we have had to date, but in particular focusing on challenges and opportunities we face as a profession.”
Acknowledging Dr. Reed V. Tuckson, immediate past executive vice president and chief of medical affairs for UnitedHealth Group and keynote speaker, Rosenfield said, “Dr. Tuckson’s broad view of the current healthcare environment will offer a first-hand perspective most physicians do not hear every day and allow us to understand our evolving role in quality improvement more clearly.” Dr. Tuckson remarked, “The urgency of time is your challenge. You simply do not have the time to only implement good ideas; you need to produce results—everybody in the healthcare community needs to produce results. The most important tool in your toolbox is the data and the analytics and a willingness to change based on the data. The field of interventional cardiology is well ahead on quality and should be commended. But there is so much more work to be done, especially as we seek to better understand this question of how best to deliver value.”
Coronary Artery Disease on the Rise in Young Adult Population
New data presented today at the SCAI 2013 Scientific Sessions show that smoking, obesity and abnormal cholesterol levels are common among patients under the age of 35 who are hospitalized with acute coronary syndrome (ACS), but the data also hinted at the possibility that excessive blood clotting may explain why these risk factors exact their price at such an early age. “Coronary artery disease is something young people need to be aware of,” said Laura Davidson, MD, an internal medicine resident at Northwestern University in Chicago.
Researchers analyzed the medical records of 124 consecutive patients under the age of 35 who were admitted to the hospital with ACS. All of the patients had coronary angiography at either Northwestern University or Vanderbilt University in Nashville, TN, and nearly half were treated with angioplasty and stenting.
The investigators found that 63% of patients had abnormal cholesterol levels, either too much LDL “bad” cholesterol (over 130 mg/dL) or too little HDL “good” cholesterol (under 40 mg/dL). In addition, nearly half of the patients (49%) were obese, 60% were smokers and 47% had high blood pressure.
Angiography revealed more signs of trouble. By threading a slender tube into the arteries of the heart and injecting X-ray dye, cardiologists were able to see blood clots in 43% of patients. Of these, 21% had a buildup of cholesterol plaque in one artery, while nearly half (48%) had plaque buildup in multiple arteries. However, in 30% of patients with blood clots, there was no angiographic evidence of coronary artery disease.
The data could also spur new research and prevention strategies. The finding of blood clots even in coronary arteries with no plaque buildup suggests that some young patients may have a blood disorder that makes them especially prone to hypercoagulability.
“We would like to do a prospective study of young patients who come in with ACS, and this time include hypercoagulation testing,” Dr. Davidson said. “If we could identify young patients at higher risk for ACS, it might lead to preventive treatments with new anticlotting regimens.”
New Statistical Analysis Predicts Renal Denervation Will Reduce Cardiovascular Risk in Patients with Resistant High Blood Pressure
Catheter-based renal denervation, a minimally invasive procedure that delivers tiny radiofrequency pulses via electrodes to the walls of the kidney arteries, is projected to improve blood pressure and substantially reduce the incidence of major cardiovascular events in patients whose high blood pressure has not been sufficiently lowered with medications. The predictions are based on a statistical extrapolation from clinical trial data and were consistent across age groups and event categories, including risk of heart attack and stroke according to researchers.
Renal denervation has previously been found to reduce drug-resistant hypertension by interrupting sympathetic nerve signals from the kidneys. Now investigators have employed a mathematical model to analyze data from the Symplicity HTN-2 randomized, controlled trial to project the clinical benefits over a 10-year period for patients who are 40, 55 and 70 years old.
“To predict event reductions and understand cardiovascular risk for a range of patient cohorts treated with renal denervation, we looked not only at data from a specific randomized trial, but also at extrapolated data for different age groups and at relatively low hypertension and high hypertension statistics,” said Jan Pietzsch, PhD, the study’s lead author and CEO of health economics consultancy firm, Wing Tech Inc., in Menlo Park, CA, and a consulting associate professor at Stanford University.
Patients in all of the age groups stand to experience clinical benefits from renal denervation, according to the statistical analysis. Among the projected benefits would be significant reductions in risk for heart attack, stroke and kidney failure.
“Pretty much across the board there are clinically meaningful reductions that we project both in terms of absolute and relative reductions of clinical events in all three age groups,” said Dr. Pietzsch.
All of the study’s relative and absolute risk predictions were applicable over a 10-year period. Results revealed predicted reductions of pretreatment systolic blood
pressure from 165 to 135 mmHg in the low range and from 190 to 150 mmHg in the high range, representing the minimum and maximum reported values for each clinical event type. The youngest group, at age 40, showed the largest relative reduction in cardiovascular risk while the oldest cohort, age 70, was projected to experience the most substantial absolute event reduction.
The model projected significantly drops in cardiovascular events across each of the three age groups and the two theoretical blood pressures (40/165 mmHg and 70/190 mmHg) at the time of treatment. For example, a more than 40% reduced risk of heart attack was projected for patients with systolic blood pressure over 190 mmHg undergoing
catheter-based renal denervation at the age of 40, and an 8% absolute reduction of risk for all coronary heart disease for those with the same blood pressure undergoing interventional renal denervation at the age of 70.
“Clinical trials will need to be completed to validate these modeled projections,” stressed Dr. Pietzsch.
Renal denervation as a treatment for hypertension has been approved in Europe but is still an investigational procedure in the United States. The Symplicity Renal Denervation System is currently under joint consideration by both the Food and Drug Administration (FDA) and the Centers for Medicare and Medicaid Services (CMS).
Minor Adjustments during Carotid Artery Interventions Can Reduce Long-Term Restenosis at Two-Year Follow-Up and May Lower Risk of Stroke Complications
For patients who received stents to restore blood flow through the main arteries supplying blood to the brain, inflating a tiny balloon inside the arteries after implantation of the stent reduces restenosis, or repeat blockages of the treated arteries, making them less likely to reclose. Modifying the order in which carotid stenting and balloon angioplasty is performed could also alter risk of stroke complications, according to the investigators of the CREST sub-student presented at SCAI 2013.
Carotid Revascularization Endarterectomy Versus Stenting (CREST) is the largest prospective randomized study comparing angioplasty and stenting of the carotid artery in the neck to surgery and is available for patients who are unable to undergo open surgery. The objective of the substudy was to evaluate whether undergoing angioplasty post-carotid
stenting increases the risk of complications (stroke).
According to Mahmoud B. Malas, MD, lead author of a substudy and associate professor of surgery at Johns Hopkins University and chief of endovascular surgery at Johns Hopkins Bayview Medical Center, “Carotid stenting is the subject of ongoing research because it provides a less invasive treatment option, which is often necessary for patients who are too sick to undergo surgery.”
Of 1109 patients in CREST who underwent carotid artery stenting, 69 patients underwent balloon deployment before the stent was implanted, 344 underwent balloon deployment after the stent was implanted and 696 patients had balloon angioplasty before and after the stent was implanted. Researchers found the risk of restenosis was reduced by 64% simply by expanding a tiny balloon, but after the stent was placed in the diseased artery rather than before it was implanted. However, the group that underwent angioplasty after the stent had a large number of strokes compared to the group who received angioplasty only prior to the stent, but that number was not statistically significant.
Results of the CREST trial also showed historically the lowest incidence of stroke as a complication of stenting and balloon angioplasty, regardless of the order. Malas concluded, “We actually had too few complications to make any statistically significant assessment about risk of stroke between the different ballooning methods.”
Results In: VERITAS Trial Confirms Safety of Live Transmission of Aortic Valve Replacement Cases
Results of the Value of Endothelin Receptor Inhibition with Tezosentan in Acute Heart Failure Studies (VERITAS) late-breaking clinical trial were presented confirming via comparison of on- and off-camera case studies that recording procedures did not pose any additional risk or complications to patients.
Dr. Ron Waksman (Washington Hospital Center, DC) said, “Live case transmission is a very effective teaching tool that allows physicians to be informed in a very clear
demonstration about degree of disease, complexity of cases and everything that the procedure entails. Our recommendation is that live cases should continue as a part of physician education.
“Transparency is very important in these procedures,” he added. “If you don’t perform them live, you don’t present all of the details and you don’t have complete transparency, which is the primary benefit and power of live case transmissions for our community of physiciansand for the public.”
Dr. Waksman explained that the FDA ruled almost a decade ago that US sites could not participate in live case presentations using investigational transcatheter aortic valves. After Waksman and others approached the FDA suggesting a study looking at safety with this class of devices, the FDA provided some funding. He noted that the bottom line is that there were no safety concerns and concluded, “I don’t know what the FDA’s reaction to this study will be, but it would be nice if they would consider the use of investigational devices in US live cases.”
Researchers recruited 64 patients across six different centers worldwide to undergo live or recorded transcatheter aortic valve replacement (TAVR), of which 46 patients were matched to a control patient who had almost identical procedures without live or recorded transmission. Matched subjects were of similar age, averaging 83 years, and they had similar valve types, which included two devices: the Edwards Sapien Transcatheter Heart Valve and a device approved for marketing in Europe called the Medtronic CoreValve Transcatheter Aortic Valve. Researchers also matched minimally invasive arterial access sites, either transfemorally (through a small incision in the femoral artery) or transapically (directly through the heart muscle wall without invasive surgery). In both groups, access was guided by catheter-based instruments and advanced imaging.
In VERITAS, patients undergoing live transmitted or recorded treatment experienced longer procedure times, about 129 minutes, versus approximately 101 minutes for matched controls not on camera (p=0.007). Final positioning of the aortic valve device was successful in 100% of both the live case and control patients. Four patients in the live or recorded cases group (8.7%) required additional implantation compared with one patient in the nontransmitted group (2.2%). Valve migration or obstruction was not experienced by either group.
Resulting complications were similar in both demonstration and control groups. The rates of death and end-organ failure were the same in both groups (2.2%, p=1). The live transmission group was associated with a lower percentage of complications than the control group for acute kidney injury (4.3% to 2.2%, p=1), post-valve heart attack (2.2% to 0.0%, p=1) and of major and minor vascular complications (6.5% to 13.0%, p=0.485 and 13.0% to 23.9%, p=0.283, respectively). None of these variations were found be statistically significant.
Pulmonary Embolism
SCAI 2013 educational focus on acute pulmonary embolism in this year’s venous program addressed one of the most widely discussed topics in cardiology and other vascular specialties in recent months. Presentations were designed to increase the awareness of the unmet need to aggressively treat submassive PE patients and the growing volume of clinical data for ultrasound accelerated thrombolysis. Dr. Piotr Sobieszczyk of Brigham and Women’s Hospital, reviewed the contemporary literature, which collectively supports risk stratification of all PE patients, identifying those at risk of poor prognosis and who demonstrates improvement in functional outcomes associated with early aggressive therapy. Dr. John Gurley of University of Kentucky followed with a comprehensive tutorial on establishing vascular access and wire/catheter navigation into the pulmonary arteries for interventions, including valuable tips and tricks in performing a safe and successful procedure.
Dr. Barry Weinstock of Orlando Regional Medical Center completed the session by presenting the most current and, historically, the only randomized controlled clinical trial on ultrasound accelerated thrombolysis for the treatment of pulmonary embolism. The study established Level I evidence on the increased clinical benefit (more improved hemodynamic recovery) with treatment using ultrasound accelerated thrombolysis over standard-of-care heparin therapy without increasing the risk of bleeding complications among submassive pulmonary embolism patients. All three panelists also supplemented with their respective singlecenter pulmonary patient series and outstanding case studies, further adding to the body of clinical evidence associated with this advanced therapy. Interest was strong and the topic elevated the interest among the attendees in PE and treatment options, as demonstrated by attendance of more than 80 physicians that filled the conference room to its capacity.
An active discussion held at the completion of the presentations allowed the faculty to address questions from the audience and further emphasized that submassive PE patients, while hemodynamically stable but exhibiting signs of right ventricular dysfunction, could deteriorate quickly if not aggressively managed, citing an analogy that these patients are just “one step away from the cliff.” On ultrasound accelerated thrombolysis, the faculty commented that hemodynamic improvement is expected in every case, typically by four to six hours into the therapy. The procedure is fast and easy and does not interrupt the flow of the cath lab. Dr. Gurley recorded a time of 26 minutes from entering into the cath lab to sending the patient to the ICU in a typical PE case treated with ultrasound accelerated thrombolysis.
With consistent results in all the cases, post-treatment lytic check is typically not performed, thus allowing the catheter to be removed at bedside and simplifying the procedure further. All in all, the attendees enjoyed the learning experience, as the faculty presented a fair and balanced review of the relevant literature and shared their accounts of a proven, leading-edge therapy that will serve the needs of treating an under-recognized and undertreated disease state.
