Cardiologists Must 'Get Up To Speed' on Treating Diabetes

Kate M. O'Rourke


June 19, 2019

Editorial Collaboration

Medscape &

Physicians across all medical specialties are aware that cardiovascular disease (CVD) is the leading cause of morbidity and mortality among patients with type 2 diabetes.

With the advent of novel antihyperglycemic agents with cardioprotective effects, why then is the majority of cardiologists caring for patients with concomitant CVD and diabetes reluctant to prescribe these drugs to their patients?[1,2,3,4,5,6]

Frequently Involved in Care More Than Ever Before

In both the inpatient and outpatient setting, cardiologists are frequently involved in the care of patients with diabetes. Robert Chilton, DO, at the University of Texas Health Science Center has seen a significant increase in the number of cardiology patients with diabetes. "I work in a cath lab as an interventional cardiologist, and 20 years ago, I would see one patient with diabetes every 2 weeks. Now, 80% of all my patients have diabetes." He further noted that cardiologists will ultimately need to become more involved in diabetes care because there are not enough endocrinologists to care for the increasing number of patients diagnosed with the disease.

Cardiologists currently see more patients with diabetes than do endocrinologists, according to a study presented at the 2019 Endocrine Society Annual Meeting in New Orleans. Among 78,878 adults with diabetes, including 31,639 with CVD, visits to cardiologists outnumbered visits to endocrinologists almost threefold.[7] When considering only patients with diabetes and CVD, there were five times more cardiologist visits (n = 43,482) than endocrinologist visits (n = 8,624).

Despite these figures, many cardiovascular (CV) specialists report being poorly equipped to address diabetes with novel agents.[4] In response to this sentiment, there has been an increase in diabetes-related continuing education programs for cardiologists.

Opportunities for Collaboration

The American College of Cardiology (ACC) and the American Diabetes Association recommend specific diabetes therapies to decrease CVD risk.[8,9] As such, a substantial opportunity exists to improve quality of care and outcomes for patients with diabetes through a more collaborative system-of-care model.

The availability of diabetes therapies to lower patients' risks of major adverse atherosclerotic events, heart failure, progression to renal disease, and premature CV death has resulted in a substantial increased interest in diabetes management across all medical specialties, including cardiology. Gregg Fonarow, MD, director of the Ahmanson-UCLA Cardiomyopathy Center, asserted, "A paradigm shift is needed to ensure that all clinicians involved in the care of patients with diabetes provide patients with optimal, evidence-based, guideline-directed care. This includes cardiologists."

New Agents, Added Cardioprotective Benefits

Newer antihyperglycemic therapies, such as glucagon-like peptide-1 (GLP-1) receptor agonists and sodium-glucose contransporter-2 (SGLT-2) inhibitors, have proven CV safety profiles and CV event reduction properties that are not yet fully elucidated and apparently not related to glycemic control.[3,5,10,11] In addition to the cardioprotective benefits, SGLT-2s and GLP-1s are associated with weight loss, another modification that reduces morbidity in patients with CVD and diabetes.[12,13]

Several of these novel agents have been approved by the US Food and Drug Administration (FDA) to not only lower blood glucose but also to prevent CVD. Liraglutide (Victoza), an injectable GLP-1, is FDA-approved for reducing the risk of myocardial infarction, stroke, and CV death.[11] Empagliflozin (Jardiance), an oral SGLT-2 inhibitor, is FDA-approved for reducing the risk of CV death. The oral SGLT-2 inhibitor canagliflozin (Invokana) is approved for reducing the risk of major CV events.[11]

Achieving the Ultimate Goal

The ultimate goal of every cardiologist should be to lower patients' risks of CV events, heart failure, and CV-related mortality. As such, cardiologists should be fully involved in managing this aspect of care for patients with diabetes. "The use of other cardioprotective therapies, particularly SGLT-2 inhibitors, should be readily prescribed by cardiologists for their patients with diabetes who are eligible," stressed Fonarow.

Chilton affirmed that the way to increase the use of these drugs is by educating cardiologists. "The SGLT-2 inhibitors are almost equivalent in horsepower for cardiovascular event reduction as statins, and cardiologists use statins all the time."

"We are at an interesting juncture now, not dissimilar to the late '80s/early '90s when cardiologists were not trained in lipids [lipid-altering agents] but needed to get up to speed once the statin trials showed cardiovascular benefits," stated G. B. John Mancini, MD, professor of medicine at the University of British Columbia.

The rapidly emerging data regarding the SGLT-2 inhibitor and GLP-1 drug classes are too compelling for cardiologists to ignore any longer. "These agents appear to be highly effective hemoglobin A1c–lowering agents but, unlike other drug classes, they have shown—even in the short term—benefits of lowering cardiovascular events, avoidance of heart failure admissions, and profound renoprotection. These benefits do not appear to necessarily be caused by A1c lowering, but the findings establish significant added value when selecting optimal medication choices for patients with diabetes, and these benefits are fundamentally important to cardiovascular specialists," explained Mancini.

Pathway to CVD Risk Reduction

Clinicians can develop treatment strategies using the 2018 ACC Expert Consensus Decision Pathway on Novel Therapies for Cardiovascular Risk Reduction in Patients With Type 2 Diabetes and Atherosclerotic Cardiovascular Disease report and other primers designed specifically for cardiologists.[1,3,4,8,9]

During his presentation at the 2019 Endocrine Society Annual meeting, Keith Ferdinand, MD, professor of medicine at the Tulane University School of Medicine and the Tulane Heart and Vascular Institute, addressed the important role of the cardiologist in treating patients with diabetes. He emphasized the need for cardiologists to familiarize themselves with novel drug indications and potential side effects to prescribe the newer diabetes medications more consistently.

Ferdinand pointed out that up to 50% of patients with diabetes may develop heart failure. The coexistence of diabetes and heart failure is associated with higher risk of hospitalization, all-cause mortality, and CV mortality.[14] In patients with diabetes, the risk for stroke is 1.6-1.8–fold greater, and the event rate for congestive heart failure is higher than that of any other complication after acute coronary syndrome (ACS).[15]Men and women older than 50 years with diabetes have reduced life expectancies of 7.5 and 8.2 years, respectively.[16]

Clinicians are eagerly awaiting results from a number of ongoing clinical trials evaluating SGLT-2 inhibitors as a treatment for acute and chronic heart failure.[17] In patients with diabetes and recent ACS, a history of retinopathy and/or neuropathy and longer diabetes duration are clinical markers for high risk of recurrent CV events.[18]

The main challenge is ensuring that competencies in understanding, diagnosing, and managing CV risks seen commonly in diabetes patients are a part of core training and basic, general cardiology practice, so that cardiologists can interact more effectively with primary care physicians and endocrinologists.

Comprehensive Care, Comprehensive Risk-Reduction

Although glucose control is critical for patients with diabetes, it is only one part of care for this patient population. Without having to manage their patients' blood sugar levels, cardiologists can still be involved in a comprehensive CV risk reduction program for patients with diabetes—one that addresses adoption of healthy lifestyle choices, blood pressure control, lipid level management, and antiplatelet therapy.[9]

According to a recent survey from Medscape and the ACC, of 621 full-time practicing clinicians involved in the diagnosis and/or treatment of patients with CVD or at-risk for CVD, most cardiologists and other healthcare professionals believe that diet and lifestyle are important factors in CV risk reduction and should be discussed with patients; however, many say they do not have the necessary tools to properly advise patients.[19]

Diagnosing prediabetes, which is often evident a decade before a diabetes diagnosis, is also essential to reducing patients' risk of progressing to diabetes. "Probably one of the easiest things is to spend time with patients who are overweight and check the labs," added Chilton.

Cardiologists should no longer be the silent partner in ensuring the use of diabetes medications with CV, heart failure, and renal benefits. "In routine cases, cardiologists can encourage and/or implement optimal medications," according to Mancini. "In more complex cases, they should be able to dialogue more effectively with primary care physicians and endocrinologists to optimize care."

Dr Fonarow is a consultant for Abbott, Amgen, Bayer, Janssen, Medtronic, and Novartis. Dr Ferdinand is a consultant for Amgen, Sanofi, Novartis, Boehringer Ingelheim, and Quantum Genomics. Dr Mancini disclosed relationships with Boehringer Ingelheim, Lilly, AstraZeneca, Novo Nordisk, Janssen/Johnson & Johnson. Dr Chilton has no relevant disclosures.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.