Does the presence of diabetes mellitus confer an increased risk of stroke in patients with atrial fibrillation on direct oral anticoagulants? A systematic review and meta-analysis

Associations of blood pressure with cardiovascular and mortality outcomes in over 2 million older persons with or without diabetes mellitus: A systematic review and meta-analysis of 45 cohort studies

BACKGROUND

The impact of blood pressure on cardiovascular disease (CVD) and mortality outcomes in older people with diabetes mellitus (DM) is not well quantified. Using a systematic review and meta-analysis of observational cohort studies, we aimed to compare the associations of blood pressure levels with cardiovascular and mortality outcomes in older people aged ≥ 65 years with or without DM.

METHODS

Studies were identified from MEDLINE, Embase, Web of Science, and search of bibliographies to July 2022. Study-specific risk ratios (RRs) with 95% confidence intervals (CIs) were pooled.

RESULTS

Forty-five unique observational cohort studies (n = 2305,189 participants) assessing the associations of systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) levels with adverse cardiovascular outcomes were included. In the general population, the pooled RRs (95% CIs) of SBP ≥ 140 vs < 140 mmHg and per 10 mmHg increase for composite CVD/MACE were 1.26 (0.96-1.64) and 1.15 (1.08-1.23), respectively. The respective estimates were 1.56 (1.04-2.34) and 1.10 (1.04-1.18) for patients with DM. SBP ≥ 130 vs < 130 mmHg was not associated with an increased risk of adverse cardiovascular outcomes in both populations. SBP < 120 vs ≥ 120 mmHg was associated with an increased risk of all cause-mortality in the general population (n = 10 studies). DBP ≥ 90 mmHg was associated with an increased risk of some adverse cardiovascular outcomes in both populations. Interaction analyses suggested similar risk of outcomes in both populations.

CONCLUSIONS

Observational evidence suggests SBP and DBP confer similar cardiovascular and mortality risk in older adults in the general population and those with DM. A blood pressure target range of > 130/80 to < 140/90 mmHg may be optimal for patients ≥ 65 years with DM, but specific targets may need to be individualised based on patients' unique circumstances. Furthermore, findings do not support stringent blood pressure control in this population group. Definitive RCTs are needed to support these observational findings.

Glycemic control and atrial fibrillation: an intricate relationship, yet under investigation

Atrial fibrillation (AF) and diabetes mellitus (DM) constitute two major closely inter-related chronic cardiovascular disorders whose concurrent prevalence rates are steadily increasing. Although, the pathogenic mechanisms behind the AF and DM comorbidity are still vague, it is now clear that DM precipitates AF occurrence. DM also affects the clinical course of established AF; it is associated with significant increase in the incidence of stroke, AF recurrence, and cardiovascular mortality. The impact of DM on AF management and prognosis has been adequately investigated. However, evidence on the relative impact of glycemic control using glycated hemoglobin levels is scarce. This review assesses up-to-date literature on the association between DM and AF. It also highlights the usefulness of glycated hemoglobin measurement for the prediction of AF and AF-related adverse events. Additionally, this review evaluates current anti-hyperglycemic treatment in the context of AF, and discusses AF-related decision-making in comorbid DM. Finally, it quotes significant remaining questions and sets some future strategies with the potential to effectively deal with this prevalent comorbidity.

Impact of preexisting diabetes mellitus on cardiovascular and all-cause mortality in patients with atrial fibrillation: A meta-analysis

OBJECTIVE

To determine the impact of preexisting diabetes mellitus on cardiovascular and all-cause mortality in patients with atrial fibrillation (AF) by conducting a meta-analysis.

METHODS

PubMed and Embase databases were comprehensively searched for relevant studies publishing until May 19, 2022. Cohort studies or post-hoc analyses of clinical trials that investigated the association of diabetes mellitus with cardiovascular or all-cause mortality in AF patients were included.

RESULTS

A total of 21 studies with 526,136 AF patients were identified. The pooled prevalence of diabetes mellitus in patients with AF was 26%. The summary multivariable-adjusted risk ratio (RR) of all-cause mortality was 1.37 (95% confidence intervals [CIs] 1.23-1.53) for patients with diabetes versus those without diabetes. Moreover, diabetes mellitus was also associated with an increased risk of cardiovascular mortality (RR 1.46; 95% CI 1.34-1.58). Stratified analyses suggested that the impact of diabetes on all-cause and cardiovascular mortality was consistently observed in each named subgroup.

CONCLUSION

The presence of diabetes mellitus in patients with AF is associated with an increased risk of cardiovascular and all-cause mortality, even after adjustment for important confounding factors.

Medical therapies for prevention of cardiovascular and renal events in patients with atrial fibrillation and diabetes mellitus

Atrial fibrillation (AF), type 2 diabetes mellitus (DM), and chronic kidney disease (CKD) are three global epidemics with significant effects on morbidity and mortality. Diabetes is a risk factor for AF, and a risk factor for thromboembolism, comorbidity, and mortality when AF is present. The pathophysiology of diabetes-related AF and interrelationships with cardiovascular events and renal events is not fully understood but is in part related to structural, electrical, electromechanical, and autonomic remodelling. The current practice guidelines offer limited recommendations on the management of patients with AF (or risk of AF) and diabetes with its own heterogeneity for the prevention of cardiovascular and renal events. This document discusses possible clinical approaches for these patients. In the last decade, there have been major improvements for the prevention of stroke in AF patients with direct oral anticoagulants, which are preferable to vitamin K antagonists for stroke prevention in DM. Because of the increased risk rate for several cardiovascular adverse events in diabetic patients, a similar relative risk reduction generally translates into greater absolute risk reduction in the diabetic population. Recent trials with non-insulin diabetes drugs using glucagon-like peptide-1 agonists and sodium-glucose cotransporter-2 inhibitors showed a significant reduction for the risk of major adverse cardiovascular events in patients with type 2 DM. Sodium-glucose cotransporter-2 inhibitors also showed a large reduction in hospitalization for heart failure and renal events, which need to be more completely evaluated in patients with AF. Mechanisms, risks, and optimal management of AF patients with DM who have or are under risk of developing heart failure or CKD are also discussed in this document. The benefits of medical therapies for these patients still need to be put into perspective, and gaps in evidence on some of these issues are likely to be addressed in future years.

Net clinical benefit of direct oral anticoagulants in atrial fibrillation patients with or without diabetes mellitus: A meta-analysis of outcome trials

AIM

To evaluate the net clinical benefit following direct oral anticoagulants (DOACs) vs warfarin by diabetes status in patients with non-valvular atrial fibrillation.

METHODS

We searched 3 electronic databases through end-February 2021 to identify relevant outcome trials in patients with and without diabetes mellitus (DM). All-cause death, non-fatal stroke/systemic embolism and major bleedings defined net clinical benefit. Outcome risk ratios and 95% confidence interval (CI), and absolute risk outcome reduction per 1000 treated patients were assessed.

RESULTS

Four trials of DOACs vs warfarin compared 22,087 patients with DM to 49,592 patients without DM. CHADS2 and 10-year fatal cardiovascular risk were higher in patients with vs those without DM (3.7 vs 2.5 and 28.4% vs 23.4%, respectively). DOACs were associated with more favorable net clinical benefit compared to warfarin in patients with and without DM (relative risk reduction, 0.85 [95% CI, 0.81-0.89] and 0.87 [95% CI, 0.79-0.96]; absolute risk reduction per 1000 patients treated, -33 [95% CI, -45, -21]) and -24 [95% CI, -43, -5]), but interaction test was not significant by relative and absolute numbers (P = 0.68 and P = 0.44, respectively).

CONCLUSION

Net clinical benefit following DOACs was not different between patients with and without DM over a period of 2.2 years.