WHO/International Society of Hypertension risk prediction charts versus the UK Prospective Diabetes Study risk engine for cardiovascular risk assessment among patients with type 2 diabetes: a comparative study.

BACKGROUND: Patients with type 2 diabetes are at increased risk of developing cardiovascular diseases, and assessment of cardiac risk is important for preventive strategies. We compared the performance of two cardiac assessment tools to predict 10-year cardiovascular risk.

METHODS: This was a retrospective study of patients with type 2 diabetes who attended two primary-health-care centres in the Gaza Strip from Sept 15 to Nov 15, 2019. We excluded patients who had any existing cardiovascular disease. 10-year cardiovascular risk assessment was done with two risk assessment tools: the WHO/International Society of Hypertension (WHO/ISH) risk prediction charts and the UK Prospective Diabetes Study (UKPDS) risk engine. We also assessed the need for prescribing statins based on the documented risk.

FINDINGS: Of 350 patients assessed, 200 were eligible for the study. WHO/ISH charts classified 135 (68%) patients as being at low of cardiac events and the UKPDS risk engine classified 100 (50%). WHO/ISH assigned 40 (20%) people to the low to moderate 10-year risk category compared with 52 (26%) assigned by the UKPDS risk engine. Agreement between the two tools was poor (p=0·01). 12 (6%) patients who were classified as being at very low 10-year cardiac risk by WHO/ISH were classified as being at very high risk when assessed by the UKPDS risk engine. Furthermore, 150 (75%) of individuals who were categorised as having low cardiac risk by WHO/ISH had higher LDL-cholesterol concentrations than the therapeutic target of 100 mg/dL. Meanwhile, the UKPD risk engine, which uses a higher number of parameters for assessment, identified these individuals as having moderate to high risk. Based on risk documented in the medical records, 33 patients needed statin therapy of whom 12 (36%) patients were receiving this treatment. Among the remaining 167 patients who did not need statin therapy, treatment was prescribed for 57 (34%).

INTERPRETATION: There is a significant discrepancy between the WHO/ISH risk charts and the UKPDS risk engine in assigning cardiac risk. Sensitivity in identifying patients with treatable levels of LDL cholesterol and diastolic blood pressure was low for both tools. Furthermore, a lack of clear local protocols led to incorrect or unnecessary prescribing. This study showed that there is a need to reconsider the use of assessment tools either by adding a new tool or by improving assessments with the current tools.

FUNDING: None.