Interpreting Absolute and Relative Risk Reduction in the Context of Recent Cardiovascular Outcome Trials in Patients with Type 2 Diabetes

Translating trial results into interpretable risk estimates: Systematic analysis of cardiorenal outcome trials of glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter-2 inhibitors

BACKGROUND AND AIMS

In a randomised controlled trial (RCT), the between-arm difference in the average probability of an event per unit of time (i.e., yearly incidence risk difference, YIRD) is an easy-to-interpret treatment effect metric. We aimed to quantify the YIRD in cardiorenal RCTs of GLP-1RAs or SGLT-2is.

METHODS AND RESULTS

We digitally searched for RCTs published up to March 1st, 2023, including subjects with type 2 diabetes randomised to GLP-1RAs or SGLT-2is and investigating cardiorenal outcomes or death. We extracted information from Kaplan-Meier (KM) plots to obtain time-to-event individual data and estimate within-arm yearly incidence risk and YIRD. Data from 19 RCTs (28 kM plots) were analysed: comparing treatment to placebo, in GLP-1RA RCTs the YIRD ranged from 0.2 % (95 % CI: -0.7 %, 1.1 %) to -1.9 % (-3.1, -0.7), for primary outcome; and from -0.2 % (-0.5, 0.2) to -0.4 % (-0.7 %, -0.0 %), for mortality. With the exception of SOLOIST-WHF (YIRD 11.9 % for primary outcome), corresponding estimates in SGLT-2is RCTs were: from -0.1 % (-0.4, 0.1) to -5.0 % (-7.7, -2.6), for primary outcome; and from -0.1 % (-0.2, 0.1) to -1.9 % (-4.4 %, 0.6 %), for mortality.

CONCLUSION

The YIRD metric complements other relative treatment effect estimates and helps quantify the absolute benefit of GLP-1RAs and SGLT-2is.

Assessment of Atherothrombotic Risk in Patients With Type 2 Diabetes Mellitus

BACKGROUND

Risk of atherothrombotic events is not uniform in patients with type 2 diabetes mellitus (T2DM). Tailored risk assessment may help guide selection of pharmacotherapies for cardiovascular primary and secondary prevention.

OBJECTIVES

The purpose of this study was to develop a risk model for atherothrombosis in patients with T2DM.

METHODS

We developed and validated a risk model for myocardial infarction (MI) or ischemic stroke (IS) in a pooled cohort of 42,181 patients with T2DM from 4 TIMI (Thrombolysis In Myocardial Infarction) clinical trial cohorts. Candidate variables were assessed with multivariable Cox regression, and independent variables (P < 0.05) were retained in the final model. Discrimination and calibration were assessed. Treatment interactions with dapagliflozin (sodium-glucose cotransporter-2 inhibitor) and evolocumab (proprotein convertase subtilisin/kexin type 9 inhibitor) were explored in the DECLARE-TIMI 58 (Dapagliflozin Effect on CardiovascuLAR Events-Thrombolysis In Myocardial Infarction 58) and FOURIER (Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk) trials, respectively.

RESULTS

Sixteen variables were independent predictors of MI or IS. The model identified a >8-fold gradient of MI or IS rates between the top vs bottom risk quintiles in the validation cohort (3-year Kaplan-Meier rate: 14.9% vs 1.4%; P < 0.0001). C-indexes were 0.704 and 0.706 in the derivation and validation cohorts, respectively. The model was well-calibrated in both primary and secondary prevention. Absolute reduction in the rates of MI or IS tended to be greater in patients with higher baseline predicted risk for both dapagliflozin (absolute risk reduction: 2.1% vs 0.2%) and evolocumab (absolute risk reduction: 3.2% vs 1.0%).

CONCLUSIONS

We developed and validated a risk score for atherothrombotic events, leveraging 16 routinely assessed clinical variables in patients with T2DM. The score has the potential to improve risk assessment and inform clinical decision-making.

Efficacy and safety profile of SGLT2 inhibitors in the elderly: How is the benefit/risk balance?

Type 2 diabetes mellitus (T2DM) is a highly prevalent health condition in the aging population. Older adults with T2DM have higher risks of cardiovascular disease, heart failure (long underestimated) and premature death than those without diabetes. Sodium-glucose cotransporter 2 inhibitors (SGLT2is) have proven their ability to improve cardiovascular prognosis and reduce the risk of hospitalization for heart failure (hHF). However, several adverse events have been reported, whose incidence and severity might be increased in the elderly population. The aims of this comprehensive review were to analyze the benefit-risk ratio of SGLT2i therapy in older patients with T2DM by collecting data from (i) large prospective placebo-controlled cardiovascular outcome trials (including those dedicated to heart failure), using both original publications and dedicated post-hoc analyses across different age groups and (ii) observational cohort studies, describing the effects of SGLT2is versus other glucose-lowering agents on cardiovascular outcomes and hHF in elderly patients or these effects in different age groups. Overall, consistent results showed a similar relative risk reduction in cardiovascular mortality and hHF with SGLT2is independently of age. The absolute risk reduction may be greater in elderly because of a higher background risk in older versus younger patients. Similarly, the safety profile of SGLT2is appeared comparable in older versus younger patients. In conclusion, the benefit/risk balance favors the use of SGLT2is in older patients at risk of cardiovascular disease and/or heart failure. Caution may be required in very old frail patients, especially those exposed to an increased risk of volume depletion.