Table 3. Results of the studies included (n = 15).

AF-Atrial Fibrillation. BMI-Body Mass Index. HbA1c-Hemoglobin A1c. QTc-QT corrected. HCM-Hypertrophic Cardiomyopathy. T2DM-Type 2 Diabetes Mellitus. SCD-Sudden Cardiac Death. N/A-Not Available.

Study		Author	Year	Type of Study	Patients	Purpose of Study	Results	Conclusion
1.	Wang et al. [16].		2020	Cohort study.	67	T2DM impact on death in patients with hypertrophic cardiomyopathy.	There is a higher rate of death within three years in hypertrophic cardiomyopathy with diabetes vs without.	Diabetes has a direct correlation with death in the first three years after ablation procedure in HCM. There are other risk factors that have independent effects as well.
2.	Leonard et al. [17].		2020	Cohort study.	Medicaid patients with T2DM.	Comparing the cases of arrhythmias and sudden death in patients taking rosiglitazone or pioglitazone.	Taking these diabetic medications has the risks of sudden cardiac arrest and malignant arrhythmias.	Both drugs have similar effects on outcomes for death.
3.	Fitchett et al. [18].		2019	Randomized control trial.	7,020	Effects of empagliflozin in type 2 diabetics with cardiovascular disease.	All patients that received the drug had a decreased mortality and cardiovascular outcome regardless of group characteristics.	Diabetics with the preexisting cardiovascular disease still benefit from pharmacological therapy with empagliflozin.
4.	Prasad et al. [19].		2019	Observational study.	338	To determine the risk factors and prevalence of silent cardiac injury in asymptomatic non-insulin-dependent diabetes mellitus. This allows detection of atherosclerosis earlier.	Patients with positive screening tools for underlying atherosclerosis were mostly diabetic males >50 years old with other risk factors for coronary artery disease.	Approximately every one in four clinically asymptomatic type 2 diabetics have silent cardiac ischemia.
5.	Kobayashi et al. [20].		2018	Cross-sectional study.	219	QT prolongation and the role of sudden cardiac death in type 2 diabetics.	There is an increased risk of prolonged QTc in patients with prolonged diabetes, female sex, insulin therapy, BMI, and systolic pressure.	As the microvascular complications progress, there is an increased risk of sudden cardiac death with prolonged QTc.
6.	Weidner et al. [6].		2018	Cohort study.	2,411	T2DM and the significance of fatal arrhythmias presenting in hospital admissions.	Diabetes when present has a higher all-cause mortality rate for cardiac arrhythmias.	The presence of non-insulin-dependent diabetes mellitus was an independent variable for survival in patients presenting with arrhythmias.
7.	Chao et al. [21].		2017	Cohort study.	>23 million	Whether AF increases the risk of sudden cardiac death.	AF along with other risk factors such as diabetes are associated with sudden cardiac death.	The risk of sudden cardiac arrest in AF was 64% higher than in non-AF patients.
8.	Charytan et al [22].		2016	Observational study.	66	Investigate incidence of sudden cardiac death in dialyzed patients.	Most individuals undergoing dialysis have underlying cardiovascular disease that predisposes them to cardiac sentinel events including sudden death.	During the dialysis cycle, patients are at an increased risk for sudden cardiac death, and placing implantable cardiac monitoring will allow immediate adjustments in the dialyzer.
9.	Eranti et al. [7].		2016	Cohort study.	10,594	Compare whether cardiac death is sudden in diabetic patients vs non-diabetic patients.	Impairment of glucose utilization subjected patients to be at higher risk for sudden cardiac death.	Diabetes increases the risk of arterial disease and the likelihood of immediate cardiac arrest.
10.	Hempe et al. [23].		2015	Randomized control trial.	10,251	Diabetics that are randomized and treated intensively produce a higher rate of adverse clinical outcomes.	Individuals in the higher hemoglobin glycation index had increased rates of hypoglycemia and mortality	Decreasing HbA1c to below 6% produced increased cardiovascular outcomes such as death.
11.	Chitnis et al. [24].		2014	Cohort study.	929	Determination of predictors for sudden cardiac death in patients with underlying heart disease.	Patients with a lower ejection fraction had a higher prevalence of diabetes.	The group with higher individuals with diabetes had a higher association with sudden cardiac death.
12.	Davis et al. [25].		2013	Cohort study.	5,102	Prevalence of silent cardiac injury in newly diagnosed T2DM and its correlation with future mortality.	Patients that had silent myocardial infarction had a higher hazard ratio for fatal outcomes and increased mortality.	20% of newly diagnosed diabetics are at risk for silent infarctions of the heart.
13.	Snell-Bergeon et al. [26].		2012	Traditional review.	N/A	Effects of hypoglycemia and cardiovascular outcomes in diabetics.	Hypoglycemia increases the risk of cardiovascular outcomes such as death and arrhythmias in the acute phase.	Trials have shown that hypoglycemia triggers physiological changes promoting cardiac disease.
14.	Chiuve et al. [27].		2011	Cohort study.	81,722 females	Approximate the effects of a healthy lifestyle in decreasing sudden cardiac death in females.	Women that had multiple low-risk factors were less likely to die from sudden cardiac etiology.	Compliance with a good lifestyle in women confers a low risk for sudden cardiac arrest.
15.	Barthel et al. [28].		2011	Cohort study.	481	Mortality risk in diabetic patients post-myocardial infarction vs non-diabetics.	SCD is highly associated with abnormal autonomic function.	The prognosis of patients post-myocardial infarction is dim in patients with autonomic neuropathies.