A recent study based on the recommendations of the European Society of Cardiology (ESC) guidelines on diabetes and cardiovascular disease (CVD) has emphasised the utility of electrocardiogram (ECG) to predict the association of heart failure in type-2 diabetes (T2D) mellitus.
The study “Diagnostic and prognostic value of the electrocardiogram in stable outpatients with type 2 diabetes” investigated 722 patients to assess whether ECG abnormalities can be used as a diagnostic and prognostic marker of heart failure (HF) in patients with T2D in secondary care diabetes clinics.
T2D is the ninth major cause of death worldwide and the number of patients living with T2D is expected to increase dramatically in the coming decades. Heart failure (HF) in patients with T2D is increasingly receiving attention due to recent cardiovascular (CV) outcome trials and found to be the second most common initial manifestation of cardiovascular disease in T2D in a cohort of 1.9 million people.
In early studies of unselected patients from primary care with suspected chronic heart failure, the presence of a normal ECG was found useful to rule out heart failure with reduced ejection fraction (HFrEF). However, this study, which was conducted with 722 people, confirms that a standard electrocardiogram when normal in stable outpatients with T2D can be used to rule out HFrEF or asymptomatic left ventricular systolic dysfunction (ALVSD).
Commenting on the implications of the study, Dr. Krupal Reddy, Specialist Interventional Cardiologist at Zulekha Hospital, Dubai said that normal ECG has more negative predictive value in ruling out heart failure. “The association of abnormal ECG and heart failure is already known. They should have studied about any specific ECG finding that is suggestive of a particular kind of heart failure,” he said.
With this study, clinicians in secondary diabetes care clinics can use an electrocardiogram to select patients to undergo echocardiography when suspecting HF with reduced ejection fraction.
Dr. Brajesh Mittal, Consultant Interventional Cardiologist at Medcare Hospitals, Dubai explained, “GPs, internists, endocrinologists and cardiologists should get an ECG done for a diabetic patient. If ECG is not normal, then appropriate further work-up such as an echocardiography should be performed,” he explained.
Dr. Mittal said that many patients have reduced heart pumping in the presence of diabetes. “A simple and quick test like ECG has been shown to predict reduced heart pumping and whether or not to proceed with further testing.”
According to the study, echocardiography, which is the gold standard in diagnosing HF, is expensive, time-consuming, and not widely available in diabetes clinics. On the contrary, the ECG is an inexpensive and easily available tool that can assist in identifying individuals with T2D at high CV risk, it said. Furthermore, the ESC recommends a resting ECG in patients with diabetes and diagnosed with hypertension or suspected CVD.
The study also examined the ability of the ECG to rule out HF in a contemporary cohort of patients with T2D. It concluded that overall ECG abnormalities were common and a normal ECG, in general, could be used to rule out HFrEF/ALVSD with a fair sensitivity and a high negative predictive value (NPV), especially in patients reporting dyspnoea.
It also noted that overall, the specificity of the ECG in diagnosing HF was around 80 per cent. The study affirmed that patients with HF had a worse prognosis compared to patients with T2D without HF, especially in the presence of an abnormal ECG. In conclusion, a normal ECG could safely rule out the presence of HfrEF/ALVSD in this population.
The study was published in the Scandinavian Cardiovascular Journal in July 2022.