ENDO Online 2020: The Endocrine Society's Virtual Meeting:

Addressing Congestive Heart Failure with Concomitant Type 2 Diabetes

with Mark Kearney, MBChB, FRCP, DM, Robert J. Chilton, DO, and Deborah Koehn, MD

Patients with type 2 diabetes are known to have more than twice the risk of developing congestive heart failure (HF), either HF with reduced ejection fraction (HFrEF) or HF with preserved ejection fraction (HFpEF).Despite the success of many antihyperglycemic medications whose function is to lower hyperglycemia, the high prevalence of congestive heart failure persists.

Photo: Sturti @ iStock

Two experts speaking at the 2019 World Congress on Insulin, Diabetes & Cardiovascular Disease (WCIRDC) discussed the practical applications required of managing heart failure in patients with concomitant diabetes, with one specialist urging clinicians to think beyond the heart in heart failure.2

Increased Risks Assocated with Elevated HFpEF in Diabetes

Mark Kearney, MBChB, FRCP, DM, the British Heart Foundation Professor of Cardiovascular and Diabetes Research, and dean of medicine at the University of Leeds in the United Kingdom, in his presentation, "Heart Failure with Preserved Ejection Fraction in Diabetes: A Benign Marker of Accelerated Aging," discussed differences between HFrEF and HFpEF and then focused specifically on the optimal management of HFpEF.

He cited guidelines from the European Society of Cardiology in the management of acute and chronic heart failure,3 which, he said, include three essential criteria in making a diagnosis of HFpEF. These include:

  • Signs and symptoms of heart failure
  • Elevated natriuretic peptides
  • Echocardiographic abnormalities of cardiac structure and/or function in the presence of a left ventricular ejection fraction of 50% or more.

Citing findings from several studies that reflect the characteristics of 959 patients suspected of having heart failure, Dr. Kearney reported that upon testing, 23% of these individuals were found not to have CHF while 44% of them had HFpEF and 33% were diagnosed on imaging as having HFrEF. 2 Those with a diagnosis of HFpEF were older, with a mean age of 83.7 years, and more women affected than men.

“They had less ischemia, less diabetes, and more hypertension," he said. And, not surprisingly, ''the patients with HFpEF had a significantly better mortality." Over five years, about 40% of those with HFpEF died in comparison to nearly 50% of those with HFrEF.2

Hospitalizations were more common in the patients with HFpEF than the HFrEF group (967 events and 692 events, respectively). However, ''the majority of [those] hospitalized in the preserved ejection group were for non-cardiovascular issues," said Dr. Kearney. The majority of patients were admitted for other causes, such as falls. 2 The take-home for clinicians? "Non-cardiovascular co-morbidity is the major challenge" in the HFpEF patients, he said.

However, a diagnosis of diabetes, when added to existing congestive heart failure, changes the treatment scenario, Dr. Kearney said. "Diabetes, even at this advanced age, required stepped-up care," he said. "We can keep these patients alive, but the burden is how to avoid hospitalization."

Beyond Cardiovascular Risks—Focusing on the VO2 Max

Giving consideration to issues of disease management in patients with heart failure is crucial, 2  said Robert Chilton, DO, associate professor of medicine and director of the cardiac catheterization laboratory at the Audi Murphy Veterans Administration/University of Texas Health at San Antonio.

In his presentation,2 Dr. Chilton advised clinicians to think beyond the basic physiology of the heart when caring for patients with congestive heart failure. These patients typically have reduced mitochondrial enzyme activity, showing electron micrographs to illustrate this point. Understanding the basic changes in peripheral vessels and molecular structure is key to managing the condition more effectively.

Understanding that patients with CHF are likely to exhibit a reduction in peak exercise oxygen consumption that leads to a decrease in mitochondrial function, he said. "Peak exercise oxygen consumption is the best predictor of timing for cardiac transplant in heart failure," he told attendees. As such, CHF patients who do not get enough exercise will be unable to extract oxygen very efficiently.2

Dr. Chilton cited recently published research by a team at the University of Pennsylvania to support the significant impact of exercise intolerance in patients with chronic heart failure.4 A compromised physical output is the hallmark of HFpEF, according to these researchers who demonstrated an association between exercise intolerance and both cardiac and peripheral abnormalities in the arterial tree and skeletal muscles.4

Having compromised mitochondrial function appears to contribute to impaired oxygen utilization, and leads to the resulting exercise intolerance in HFpEF.4 From other research findings,5 there is evidence that sodium-glucose transport protein 2 (SGLT2) inhibitors, leading to elevations in erythropoietin, hemoglobin, and hematocrit in those with type 2 diabetes, may result in a reduction in the progression of chronic kidney disease, lower overall mortality, and a decreased risk of hospitalization rates associated with heart failure.

"Keeping that oxygen consumption up is quite important," Dr. Chilton said. "Maybe monitoring hematocrit and bringing more oxygen to the area will provide an effective approach in helping people to respond more favorably." He added: "if you want to predict death [from CHF], it's not the ejection fraction that should be of paramount concern but the actual utilization of oxygen that will determine the patient’s outcome."

As with many aspects of endocrine care, lifestyle behaviors remain a key controllable component in the management of patients with both type 2 diabetes and heart failure, as reflected in the treatment guidelines from the American Heart Association and the Heart Failure Society of America.6

In response to findings reported out of the HF-ACTION trial in which 2,331 people with HFrEF were assigned to exercise training or optimal medical care, participants with diabetes who were assigned to exercise were reported to have significant improvement in peak oxygen consumption and 6-minute walk distance (both P < 0.001) compared to usual care.7

During the question and answer session, one attendee asked about the value of exercise testing and whether it should be reinstated as a regular assessment tool, considering the research that VO2 max may predict outcome. Dr. Kearney responded that in the United Kingdom, VO2 max testing is currently ordered routinely.

Dr. Chilton added that given the clear and growing evidence of oxygen consumption as a leading factor in CHF outcomes, he thinks it will come back in the US, too but ''it may take a while to catch on."

Need for Greater Attention to CHF in Diabetes Patients

The findings presented in this session ''reinforced the importance of appropriately identifying patients with congestive heart failure," said Deborah Koehn, MD, assistant clinical professor of internal medicine and adjunct assistant clinical professor of endocrinology at Virginia Commonwealth University, in Richmond. Another takeaway point: It is crucial that we go further to identify the form of heart failure present in our diabetes patients, Dr. Koehn told EndocrineWeb.

"We have good treatments for patients exhibiting reduced ejection fraction," she said, citing ACE inhibitors and betablockers. However, its evident that treating patients with HFpEF is a bit more complicated.

The evidence to date also underscores how diabetes affects comorbidities such as CHF, said Dr. Koehn. "As soon as you throw in that diabetes piece, it flips the switch," meaning the need to test for and treat the specific causation of congestive heart failure is ratcheted up.

Dr. Chilton's talk should serve as a reminder to clinicians that ''diabetes affects everything," and act as a promote to always look beyond the heart, giving particular consideration to the patient’s VO2 max. Recent research suggests that prescribing SGLT2 inhibitors may help increase hemoglobin and hematocrit levels, even as their use is still relatively uncommon, Dr. Koehn said.

As such, this session served as a valuable remind of the benefits that be gained from SGLT2 inhibitors and to consider adding them to the treatment plan in appropriate patients.

Dr. Kearney reports receiving lecturing fees from Merck; Dr. Chilton is on advisory boards for Takada, Bristol-Myers Squibb, Merck Sharp & Dohme and Boehringer Ingelheim. Dr. Koehn reports no financial conflicts. 

Next Summary:
Treating Diabetic Nephropathy: Which Way Forward in Patient Care?
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