Take Advantage of Growing Evidence of Effectiveness
By: Linda Harder
Photography by: Tracey Brown
When should you refer a patient to avoid subjecting him or her to unnecessary or unproven cardiac procedures? Maryland Physician interviewed three Maryland cardiac specialists to provide the latest information on newer techniques to manage patients with mitral valve damage, chronic total occlusions and atrial fibrillation (A-Fib).
Minimally Invasive Valve Repair Proven Effective
“The most important trend in heart surgery over the past decade is the transition to a minimally invasive (MI) platform,” says Paul 
Massimiano, M.D., program director for Cardiac Surgery at Washington Adventist Hospital. “Anything we traditionally did through the front can now be performed less invasively.
“In the 1990s,” he continues, “we began paving the way with cannulas in the groin, accessing the femoral artery and vein through those and using smaller incisions to gain access to the heart.”
Dr. Massimiano specializes in mitral valve repairs. While MI approaches to this procedure have been performed since the late 1990s, a surprisingly small percentage – only 10 to 15% – of mitral valve procedures in the U.S. are currently performed this way. In addition to being more technically challenging and taking more OR time, the MI approach has a steep learning curve. “These are some of the reasons it hasn’t taken off more,” says Dr. Massimiano.
There are three possible MI techniques – robotic, direct vision, and thoracoscopic. The direct vision approach is used for the majority of cases because the results are consistently superb. “There’s been a big debate about robotic versus non-robotic approach,” Dr. Massimiano notes. “Both are good, and both have demonstrated excellent results. As the surgeons in our practice have become more experienced with MI approaches, we’ve used the robot less with comparable results.”
Dr. Massimiano adds, “Most patients are candidates for the MI approach, with the few exceptions including those with markedly reduced heart function or significant peripheral vascular disease. There really is no age cut-off now, either – some of our patients are in their 80’s.”
After more than a decade of results, numerous studies have shown the MI approach to be safe and to provide results comparable to an open incision. As is true of many surgical procedures, high volumes and experience are important. “The key to success is proper selection of the patient, as well as the surgeon and center,” notes Dr. Massimiano.
Both the techniques and the instruments in valve repair procedures have progressed. The MI incisions are only five to six centimeters in length, thanks to improvements in equipment and techniques. Catheters and cannulas can be inserted percutaneously using thinner, smaller, and more flexible devices.
The advantages of the MI approach for patients are clear – most patients go home Day 2 post-op and 20% go home Day 1. The average length of stay is three-and-a-half days versus five to six days for an open incision, but the real benefit to patients is their ability to resume work and most activities within a few weeks instead of months.
Dr. Massimiano urges referring physicians to refer patients early. “The data shows the importance of this. The AHA guidelines provide excellent guidance for referring physicians. If you wait for symptoms or for chamber enlargement, you’ve probably waited too long. “
New Techniques Boost CTO Success Rates
Angioplasty and stenting have become so successful in treating most coronary blockages that it can be frustrating to manage coronary chronic total occlusions (CTO), which until recently had a far lower success rate than other percutaneous coronary interventions. CTOs involve complete blockages of coronary arteries for more than three months. They are most common in the right coronary artery with the remainder evenly split between the left anterior descending (LAD) and circumflex arteries. These blockages consist of hard plaques made of dense, fibrous tissue and calcification at the proximal and distal ends.
Patients often slowly develop small collateral vessels to restore limited blood flow, and may not recognize their symptoms because they slowly adapt to their limitations. In the event a patient develops blockages in the “normal” blood vessel providing the collateral flow to the CTO, they are at a higher risk for myocardial infarct (MI) and death.
“CTOs represent the last frontier for coronary intervention,” says John Wang, M.D., chief, cardiac catheterization laboratory, Union Memorial
Hospital. “A conservative estimate of their prevalence is that they represent about 20% of patients in the cath lab.”
With conventional wire escalation techniques, interventionalists have about a 50/50 chance of opening the blockage with angioplasty. This approach is time consuming and entering into the true lumen is highly challenging.
Recent advances in angioplasty techniques for CTOs have dramatically improved the odds for these patients, with success rates approaching 90% when the newer techniques are employed.
“We’ve done about 15 of these procedures since August, 2011,” notes Dr. Wang. “Before, we had no hope of getting into some of these blockages. Which approach to start with is case dependent, as every angiogram has specific nuances. With the new ‘antegrade’ technique, we use a “CrossBoss™ CTO Catheter that has a blunt, rounded tip. Instead of going through the true lumen, we go into the wall of the blood vessel and track subintimal, then re-enter the true lumen with a Stingray™ CTO Re-Entry System. It’s like running ductwork to the second floor of your house behind the drywall. Once we enter a softer area, we can make a new channel to put the stent into the true lumen.”
Dr. Wang continues, “A second new ‘retrograde’ technique approaches the blocked coronary artery from the other side. For example, in a 100% blocked right coronary artery (RCA) that is collateralized by the LAD, we would wire the septal perforators from the LAD to enter into the distal RCA. We then probe the occlusion from the back side, which typically is much softer and easier to cross.”
Physicians are encouraged to refer patients for evaluation of their CTOs. ‘There are many patients who have CTOs that are being medically managed right now because there were no good options before” Dr. Wang says. “Once you start looking you realize that there are many patients that would benefit from this technology. To determine if they’re a candidate, we need to see their cath films and speak with them and their referring physician.”
With the new CTO techniques, patients typically go home the next day. They can resume normal activities at the same rate as other angioplasty patients.
‘This represents an exciting new option for CTO patients,” Dr. Wang concludes. ‘It’s allowing a whole subset of patients to have options.”
Dispelling Atrial Fibrillation Myths 
Baran Kilical, M.D., F.A.C.C., cardiac electrophysiologist (EP) at Anne Arundel Health System, spoke to Maryland Physician to dispel some common myths about the best way to manage A-Fib. Dr. Kilical sees numerous patients with this common condition and understands that it can be frustrating to manage.
Myth #1
Anti-coagulants unnecessary after achieving normal sinus rhythm
“A common misconception among patients is that if you maintain sinus rhythm, your risk of stroke decreases and you can stop taking anti-coagulation medications,” Dr. Kilical comments. “That’s a mistake. The American Heart Association guidelines recommend continuing anti-coagulation based on your CHADS score (an acronym of the five key risk factors for stroke following A-Fib – congestive heart failure, hypertension, age, diabetes and stroke or TIA history) regardless of a successful ablation. Catheter ablation is reserved for symptomatic patients to eliminate symptoms and anti-arrhythmic medications, but not to stop anti-coagulation.”
Myth #2
Dabigatran superior to warfarin
Dr. Kilical says, “The reality is that, for all practical purposes, their efficacy is equal. The main advantage of PRADAXA® (dabigatran) is that you don’t have to take dietary precautions or check the international normalized ratio (INR) regularly. The Randomized Evaluation of Long-Term Anticoagulation Therapy (RE-LY) trial found that the risk of major bleeding with warfarin at the end of two years was 7%, vs. 6% with dabigatran. The risk of a hemorrhagic stroke was 0.75% with warfarin and 0.72% with dabigatran. As a new medication, it is considerably more costly than warfarin, although it doesn’t involve regular blood work. “
Myth #3
Aspirin appropriate for CHADS Score of 1
EPs have long used the CHADS Score to guide the use of anti-coagulants. Having two or more factors warrants the use of an anti-coagulant, while a score of 0 indicates that no anti-coagulants are required. A CHADS score of 6 is associated with an annual risk of stroke of 18.2%, whereas a score of 0 is associated with only a 0.5% risk of stroke. The controversy arises when patients have a score of 1.
“The AHA guidelines say you can use either aspirin or warfarin for this group,” says Dr. Kilical. “I tend to use blood thinners for these patients, because bleeding can be controlled, but a stroke is a devastating event. Most of the studies, except for the Stroke Prevention in Atrial Fibrillation (SPAF) trial, concluded that aspirin was of little or no benefit. Most EPs say that taking aspirin is treating the doctor, not the patient.” However, he notes that he sometimes prescribes aspirin when a patient is opposed to using warfarin.
Myth #4
Ablation reserved for sickest patients
“The truth is,” Dr. Kilical observes, “after one episode of failure after medication, or for those who have side effects from medication, you’re a candidate for ablation. In fact, ablation is less beneficial for the sickest patients; paroxysmal A-Fib patients benefit the most. “
The success of ablation is dependent on:
- A-Fib duration
- Ejection fraction
- Left atrial size
- Mitral regurgitation
- Sleep apnea
Catheter ablation success rates have increased in recent years, thanks to a better understanding of the disease, new techniques and technology, and more experience. Early ablation success rates were 60% or more for paroxysmal A-Fib and 30% or less for persistent A-Fib.
Dr. Kilical notes, “Now, some 80% of patients undergoing ablation are successful, meaning they are free from A-Fib for at least 12 months without taking medications.
Ablation used to involve a long, difficult procedure. However, with new catheters that can deliver circular lesions, improved 3-D mapping, and a growing arsenal of new tools, the procedure is faster, safer and more successful.”
The new ablation procedures can involve FDA-approved radiofrequency (RF) energy to destroy tissue through resistive and conductive heating, or cryoablation, which effectively destroys tissue by freezing.
Dr. Kilical reminds physicians, “Keep in mind, A-Fib begets A-Fib. I prefer to perform ablation before A-Fib becomes permanent. A-Fib is progressive, with increased frequency and duration secondary to the inflammation and scarring in the myocardium. It’s best to refer patients while their A-Fib is still paroxysmal and can be more readily treated.”
Paul Massimiano, M.D., program director for cardiac surgery, Washington Adventist Hospital.
John Wang, M.D., chief, cardiac catheterization lab, Union Memorial Hospital.
Baran Kilical, M.D., cardiac electrophysiologist, Anne Arundel Health System.
This is some text prior to the author information. You can change this text from the admin section of WP-Gravatar To change this standard text, you have to enter some information about your self in the Dashboard -> Users -> Your Profile box. 
