Some diabetes mellitus is a precursor to heart failure! A review by Harvard Medical School

In recent years, guidelines have consistently recommended screening for patients at high risk of heart failure. The Framingham study confirmed that diabetes increases the risk of heart failure by 4 to 5 times.

Recently, scholars from Harvard Medical School published a commentary article, pointing out that according to the new ACC/AHA universal definition and classification of heart failure, diabetic patients with a long history of disease, poor blood sugar control, and diabetic microvascular complications, such as diabetic retinopathy and diabetic nephropathy, are in the early stages of heart failure (i.e. stage B heart failure).

The authors note that the number of patients with stage B heart failure is four times that of patients with stage C and D heart failure combined. However, these high-risk patients are often underestimated in clinical practice.

An increased urine albumin/creatinine ratio (UACR) and a decreased eGFR indicate the presence of microvascular complications in diabetes. From the perspective of diabetes management, it is important to screen for diabetic cardiomyopathy at this clinical stage.

Diabetic cardiomyopathy is a specific form of heart disease in which structural abnormalities of the heart result from underlying metabolic derangements associated with diabetes, in the absence of known risk factors such as hypertension and coronary artery disease.

Among patients with diabetes, factors associated with heart failure include age, duration of diabetes, poor glycemic control, urine albumin-to-creatinine ratio, peripheral vascular disease, ischemic heart disease, and obesity.

In 2017, the AHA/ACC/HFSA heart failure management guidelines recommended, based on the results of the STOP-HF study, that heart failure screening should be based on BNP, which can reduce the occurrence of asymptomatic left ventricular dysfunction and reduce hospitalizations accordingly.

The PONTIAC study found that the use of RAAS blockers and beta-blockers reduced cardiovascular events compared with conventional treatment in diabetic patients with elevated NT-proBNP but without heart disease.

In the STOP-HF and PONTIAC studies, the BNP (≥50 pg/ml) or NT-proBNP (>125 pg/ml) levels used to identify eligible patients were significantly lower than those required for diagnosis of heart failure.

Cardiac ultrasound can reveal a variety of abnormalities in patients with diabetic cardiomyopathy, including increased left ventricular mass, increased ventricular wall thickness, left atrial enlargement, left ventricular diastolic dysfunction, and impaired global longitudinal strain (GLS).

Specifically, echocardiographic diagnosis of diabetic cardiomyopathy should include the presence of at least one of the following:

(1) Left ventricular hypertrophy (LVH): defined as left ventricular mass index (LVMi) >115 g/cm2 (male) or >95 g/cm2 (female).

(2) Left atrial enlargement: defined as left atrial volume index (LAVi) ≥ 34 ml/cm2.

(3) Abnormal ratio of mitral inflow peak early diastolic velocity (E) to tissue Doppler mitral annular early diastolic velocity (E′), defined as E/E′ ≥ 13

(4) Overall long axis strain is damaged