In recent years, heart failure has been recognized as a common complication of diabetes, with up to 22% of people with diabetes having heart failure. Heart failure can occur in people with diabetes even in the absence of traditional risk factors, like coronary heart disease or hypertension (high blood pressure).
A Consensus Statement from the American Diabetes Association (ADA) was recently published, recommending that people with diabetes should have routine annual blood testing to screen for heart failure.
The statement, endorsed by the American College of Cardiology, discusses many aspects of heart failure, from risk factors, to assessment, diagnosis, staging and treatment. I encourage all health care providers who treat people with diabetes to read it in its entirety (it’s a free download). Here I am focusing on just a few points from this excellent document:
On the risk of heart failure (HF) in people with diabetes:
- People with diabetes or prediabetes have a 2-4 times increased risk of HF compared to people without.
- HF may be even more common in people with type 1 diabetes than type 2 diabetes (though common in both).
- Women are at higher risk of HF than men (especially women with type 1 diabetes); though note again that HF is common in men AND women , with type 1 OR type 2 diabetes.
Risk factors for HF in people with diabetes include:
- longer duration of diabetes
- poor control of sugars
- high cholesterol
- elevated body weight (obesity)
- kidney disease, including protein in the urine (albuminuria)
- ischemic heart disease
- peripheral vascular disease
A game changer in clinical practice is the recommendation to screen people with diabetes every year for HF with blood tests, especially if there are risk factors for HF (including the list above, also female gender, and those that may have social determinants that may impact their care – see Figure 1 in the paper). Suggested tests, and cutoff values, to determine HF risk include:
- NT-pro-BNP: 125 pg/mL
- BNP: 50 pg/mL
- high sensitivity cardiac troponin : >99th percentile upper reference limit
While this recommendation for routine blood test screening has not been implemented in Canadian heart failure guidelines, it certainly gives the Canadian health care provider cause to stop and think about this.
NT-pro-BNP, which is probably the best accepted blood test for screening for heart failure, is restricted to order only by certain physicians (eg cardiologist) in some provinces. Also, it can be elevated in people with chronic kidney disease or atrial fibrillation, and lower in people with obesity. As noted by the consensus statement, a negative test result (below the limits above) is quite good to rule out heart failure (high negative predictive value). However, there should be a higher clinical suspicion for HF in people who have structural heart issues (Stage B in Figure 1), or obesity with symptoms that are often ascribed to obesity itself, but could be due to HF (eg shortness of breath with exertion or laying down, weight gain, fatigue – Stage C/D in Figure 1), even if the blood tests are reassuring.
On the other side of the coin, a positive routine screening blood test doesn’t guarantee that heart failure is present, but requires careful further evaluation to determine if heart failure is present.
It remains important to clinically screen our patients with diabetes for heart failure by asking about symptoms, as well as physical examination. Any suspicion of HF should prompt investigations, including not only blood testing, but other tests like chest Xray and echocardiogram (heart ultrasound), and possibly a consultation with a cardiologist. Whether routine annual blood testing to screen people with diabetes for heart failure will become recommended in Canada remains up for (a very interesting) debate!
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