THE BEAT GOES ON

Despite the challenges of a global pandemic and of significant limitations in clinical research (due to reduced voluntary patient participation), the past 18 months have been invaluable in the fields of cardiology research and new product development. Global challenges have included learning how to care for COVID-19 patients experiencing acute cardiac emergencies, and relying on remote webcam evaluations to make critical decisions in order to keep ourselves safe. Doctors had to develop and practice new protocols for managing acute cardiac decompensation (aka heart failure) in COVID patient populations of varying ages, due to heart inflammation or to a heart attack resulting from clotting abnormalities. Lifesaving care for these patients was delivered while wearing several layers of personal protective gear to protect physicians and health care professionals from contracting COVID themselves. In most cases, persistence, dedication and perseverance saved lives, although there were still a large number of deaths due to COVID infection.

Despite these unique circumstances, there have been significant advances in preventive cardiology and in nonsurgical treatment of chronic cardiac diseases.

BY SANJAY DHAR, M.D.

NON-STATIN DEVELOPMENTS

Patients with high cholesterol and associated cardiovascular disease are usually treated with escalating doses of statins (a group of medicines that can help reduce the level of low-density lipoprotein LDL cholesterol in the blood), in addition to recommended lifestyle changes, to achieve certain therapeutic goals. bout to 10 percent of patients, however, can’t tolerate statins due to side effects, most commonly muscle aches and pains. Until recently, there weren’t many alternatives, but now patients have choices outside of statins.

Non-statin drugs, such as evolocumab and alirocumab, have dramatically helped reduce cholesterol levels to numbers that were not previously possible. These drugs inhibit PCSK9 (proprotein convertase subtilisin-kexin type 9), a protein that’s made in the liver. Research has proven that people with high levels of PCSK9 tend to have high cholesterol throughout their lives and develop heart disease early. People with low levels of PCSK9 tend to have low cholesterol and a lower risk of heart disease. This research has led to the successful development of PCSK9 inhibitors to lower cholesterol.

Another non-statin drug, bempedoic acid, blocks an enzyme in the liver called ATP (adenosine triphosphate citrate lyase), which is involved in making cholesterol. Like statins, it also blocks a pathway in production of cholesterol in the liver, but without any statin-related side effects.

Other medications showing promise include over-the-counter omega-3 fatty acid supplements. The U.S. Food and Drug Administration (FDA) recently approved a highly purified omega- supplement which helps lower cholesterol and triglyceride levels and also shows a reduction in overall cardiovascular related morbidity and mortality. (See rusted hird-Party ertifiers, page 22 to learn about wisely choosing O supplements.)

Recently, there’s been a resurgence in using the drug colchicine, which is typically

used to treat gout, to reduce in ammation caused by acute and chronic coronary artery disease. Previously, colchicine was used to reduce in ammation in patients with pericarditis (in ammation of the heart covering, or pericardium). However, recent studies have shown it to improve survival rates in patients with chronic coronary disease who are already receiving lipid-lowering and antithrombotic therapy such as aspirin.

TREATING CORONARY BLOCKAGES

There have also been important new developments in treating complex, resistant coronary blockages. For example, infrared spectroscopic imaging of coronary arteries — using light with a longer wavelength and lower frequency than visible light — enables early detection of unstable plaques (fatty deposits that collect on arterial walls, causing clogs and damage). Once detected, plaques can be targeted for aggressive primary and secondary preventive therapies to limit plaque rupture and subsequent heart attacks.

Intravascular ultrasound (IVUS) is a catheter-based diagnostic detection procedure that uses sound waves to produce an internal image of the coronary artery. IVUS can quantify the percentage of arterial narrowing and give insight into the nature of the plaque.

Another catheter-based detection device is the instantaneous wave-free ratio (iFR), used to evaluate whether a blockage is causing limitation of blood ow in coronary arteries. It is also used to help guide deployment of balloons and stents in coronary arteries; a stent is a tiny mesh tube that’s inserted into an artery, then expanded using a balloon and fixed in place to help keep the artery open.

Once detected, the newest technique available for managing resistant blockages is cardiac shock wave therapy ( SW ), similar to the technique used to break up kidney stones. SW uses low-energy, high-voltage, high-frequency electromagnetic ultrasonic pulses to disrupt rigid calcium deposits in coronary arteries, facilitating implantation of coronary stents.

Advances in coronary stents include a new generation of drug-eluting stents (DES) that are coated with a slow-release medication to help prevent blood clots from forming within them. These include stents with ultrathin struts (support framework), making their placement easier even in challenging situations. What’s more, they are nano-coated with new biodegradable polymers that target drug delivery to reduce narrowing (restenosis) and scar formation within the stent. These developments have reduced the time requirement for subsequent and prolonged use of blood thinning medications.

HEART VALVE PROBLEMS

Advances in managing structural valvular heart disease, both congenital and developed over time, have allowed for percutaneous treatment rather than open heart surgery. Initial success in managing diseased aortic valves (TAVI), has led to the proliferation of new devices in the management of diseases affecting the mitral, tricuspid and pulmonic valves. Because of these advances, it’s conceivable that, in the near future, few patients will have to undergo open heart surgery for heart valve replacement.

These gains in treating advanced heart valve conditions have resulted from active and effective collaboration between biomedical engineers and physicians. Advances in alloy technology and nanotechnology have also helped make great strides in this field. MORE THERAPEUTIC ADVANCES

Hypertension a icts almost every race and ethnicity with long-term catastrophic consequences. A huge assortment of blood pressure medications is available to manage the problem, but some patients are simply resistant to drugs and therapy.

Management of drug-resistant or di cult-to-treat hypertension using a minimally invasive procedure called renal denervation strategies (RDN) has been studied for a while and is now ready for prime time. RDN uses radiofrequency ablation to burn the nerves in the kidney’s blood vessels. This process causes a reduction in the nerve ac-

SIGNIFICANT ADVANCES IN OUTCOME BENEFITS, THERAPEUTIC TECHNIQUES, AND DEVICE INNOVATIONS AND INVENTIONS HAVE RESULTED IN SIGNIFICANT dition — as seen in sudden cardiac deaths in IMPROVEMENT IN CARDIAC CARE. young athletes — didn’t have a therapeutic option until now. Mavacamten, a new drug on the market, reduces heart muscle contractility, which directly reduces the stress within the heart and, hence, prevents catastrophic complications.

tivity around the kidneys, which indirectly decreases blood pressure.

Advances in cardiac electrophysiology (a test performed to assess the heart’s electrical system or activity) have focused on ablation to treat atrial fibrillation at a much earlier stage of the disease, rather than waiting until an arrhythmia has become unmanageable and resistant to all cardiac suppressive medications. Arrhythmia detection and management has also become easier with advances in cardiac equipment, which can reduce the time a patient has to be under anesthesia for the procedure.

Other advances include stroke risk prevention in patients with arrhythmias who can’t take blood thinners. This is achieved by deploying a tiny device that plugs the left atrial appendage (an extraneous yet naturally occurring protrusion in the upper left part of the heart), which is notorious for clot formation. These devices are implanted percutaneously, meaning the procedure does not require open heart surgery.

BATTLING HEART FAILURE

New therapies have also been introduced for managing patients with heart failure.

Heart failure has a significant negative socio-economic impact in our society. It’s projected that 0 percent of cardiac diseaserelated expenses (reaching 0 billion per year domestically) are due to heart failure and associated hospitalizations. In response, there’s been a significant push to develop new strategies to help patients while, at the same time, lowering costs related to repeated hospitalizations.

New medication classes to treat heart failure have shown remarkable success and continue to grow. These include sodium-glucose cotransporter 2 (SGL 2) inhibitors sotagli ozin, empagli ozin, and dapagli ozin, drugs originally designed to treat diabetes patients. Research has shown them effective in treating heart failure even for patients without diabetes.

Other pharmacological advances include vericiguat, which helps relax the blood vessels and indirectly reduces stress on the heart; omecamtiv, which improves cardiac contractility and directly helps patients with poor cardiac function; and the combination sacubitril/valsartan (marketed as Entresto), which works in two complementary ways to effectively lower blood pressure.

Hypertrophic cardiomyopathy is a condition in which the heart muscle becomes very thick, making it harder to pump blood. This relatively dangerous, often undetected conDEVELOPING TREATMENTS

rtificial Intelligence ( I) is still in its infancy in the field of application cardiology, yet AI algorithms are already being used to automatically detect arrhythmias and send alerts to patients using wearables or smartphone-based apps that record ECG. Examples of this technology are the Apple watch and the Alivecor KardiaMobile device (see now Your Numbers, page 60, for more about AliveCor). AI will likely see its biggest steps in the coming years for pointof-care (POC) triage apps and wearable cardiac monitoring technologies. This will speed the process of getting at-risk patients examined by a cardiologist and aid in earlier detection of cardiovascular diseases.

Although cardiac medical advances were lessened in 2020-2021 by the O ID pandemic, due to reduced research funding and low patient participation, adaptability, new technologies and applications allowed us to manage both cardiac complications due to COVID infection, as well as innovate therapeutic strategies in structural, coronary, cardiomyopathic and arrhythmogenic diseases.

Significant advances in outcome benefits, therapeutic techniques, and device innovations and inventions have resulted in significant improvement in cardiac care. These goals were only achieved due to the dedication and hard work provided by teams of cardiologists, cardiac surgeons, bio-engineers, nano technologists and many other medical personnel. We will continue to work to provide for a better future in health care.

About the author: Dr. Sanjay Dhar is a practicing clinical cardiologist with Providence Medical Group in Santa Rosa. He is the chief of cardiovascular diseases at Santa Rosa Memorial Hospital.