DIABETES AND THE RISK OF HEART FAILURE PROGRESSION

What is diabetes?

Diabetes is a condition characterized by reduced insulin secretion and changes in peripheral insulin resistance, leading to elevated blood sugar levels. Early symptoms are related to increased blood glucose and include increased thirst, frequent urination, and blurred vision. Late complications include cardiovascular disease, peripheral neuropathy, kidney disease, and susceptibility to infections.

Diabetes and the Risk of Heart Failure Progression

Diabetes is a significant factor to consider in the assessment of heart failure patients. It not only contributes to atherosclerosis, narrowing/obstructing coronary arteries that supply the heart, but also increases myocardial fibrosis, inflammatory responses, and structural changes that lead to decreased heart function, ultimately resulting in heart failure.

A recent study published in JACC, conducted on nearly 4800 heart failure patients without clinical symptoms (such as difficulty breathing, swollen ankles, etc.), revealed that 30% of these patients had diabetes.

Heart failure patients were categorized into the following groups:

• The asymptomatic group is divided into stage A heart failure (only risk factors for heart failure such as coronary artery disease, stroke, hypertension, obesity, and chronic kidney disease, without structural or functional changes in the heart).
• Stage B heart failure comprises patients with structural/functional changes in the heart or abnormalities in cardiac enzymes or B-type natriuretic peptide (BNP).

Over a median follow-up of 7.5 years, the results showed that the diabetes group had a higher risk of progressing to symptomatic heart failure (stages C and D) compared to the non-diabetes group. Diabetes patients with stage B heart failure had a 4-fold increased risk of heart failure progression compared to those in stage A. Particularly, diabetes patients with poorly controlled blood sugar (HbA1C > 7%) in stage B had a 7.6-fold increased risk of heart failure progression. Even with well-controlled HbA1C, the risk of heart failure progression in the stage B group remained elevated at 4.6 times.

Challenges in diagnosing, evaluating, and monitoring diabetes complications

Monitoring cardiovascular complications in diabetes patients is commonly practiced, but the obstacle lies in many cases being limited to electrocardiograms or basic echocardiography. Electrocardiogram evaluations mainly focus on coronary artery disease; however, 50% of cases with coronary artery disease may appear normal during resting ECG.

With basic echocardiography, if the assessment relies solely on ejection fraction (EF) or regional wall motion, structural/functional changes in stage B heart failure may be overlooked. An estimated 30-40% of heart failure cases with preserved EF (EF ≥ 50%) are diabetes-related. Few patients in clinical settings undergo in-depth assessments with parameters such as left ventricular mass index, strain rate measurement, or assessment of left ventricular filling pressures.

Another crucial point is that many diabetes patients have poorly controlled HbA1C levels and may not be using proven cardiac medications like SGLT2 inhibitors or GLP1 agonists.

Heart failure is the ultimate destination for many types of cardiovascular diseases. Waiting for clear symptoms before starting treatment is not advisable. Heart failure with symptoms (stages C, D) constitutes only about 10% of heart failure patients, with a 5-year survival rate of 75% and 20%, compared to over 95% in stages A/B.

From a cardiovascular prevention perspective, this study emphasizes the need for early action, thorough examinations, and regular health screenings. Investing time and effort in a more in-depth evaluation can provide the most benefit to diabetes patients in the stage of heart failure before symptoms manifest.