Prognostic significance of diabetes in acute myocardial infarction. Are the differences linked to female gender?

Sex-gender-related therapeutic approaches for cardiovascular complications associated with diabetes

Diabetes is a chronic disease associated with micro- and macrovascular complications and is a well-established risk factor for cardiovascular disease. Cardiovascular complications associated with diabetes are among the most important causes of death in diabetic patients. Interestingly, several sex-gender differences have been reported to significantly impact in the pathophysiology of diabetes. In particular, sex-gender differences have been reported to affect diabetes epidemiology, risk factors, as well as cardiovascular complications associated with diabetes. This suggests that different therapeutic approaches are needed for managing diabetes-associated cardiovascular complications in men and women. In this review, we will discuss about the sex-gender differences that are known to impact on diabetes, mainly focusing on the cardiovascular complications associated with the disease. We will then discuss the therapeutic approaches for managing diabetes-associated cardiovascular complications and how differences in sex-gender can influence the existing therapeutic approaches.

Electrocardiographic Left Ventricular Hypertrophy Among Gambian Diabetes Mellitus Patients

BACKGROUND

The global prevalence of diabetes and its complications is increasing worldwide. Its role in coronary heart disease has been linked with the presence of left ventricular hypertrophy (LVH). The present study aims to determine the prevalence of electrocardiographic left ventricular hypertrophy (ECG-LVH) in adult diabetic subjects, its epidemiological and clinical correlates.

METHODS

A descriptive cross-sectional study involving 534 patients was conducted at the Edward Francis Small Teaching Hospital (formerly Royal Victoria Teaching Hospital), The Gambia. Four hundred and forty patients were included using a standard questionnaire. Anthropometry, laboratory investigations and electrocardiogram were carried out. We used the Lewis, Cornell, and Sokolow-Lyon Voltage criteria to define ECG-LVH. Minitab™ statistical software version 13.20 was used for analysis.

RESULTS

146 (35.2%) patients had ECG-LVH using all 3 criteria and this prevalence was higher among women being 116 (79.5%). A generally high prevalence of overweight (155/37.4%) and obesity (119/28.6%) was observed among study participants, and both clinic-day systolic and diastolic blood pressure (BP) were significantly higher in those with ECG-LVH. Poor diabetes control was observed in both groups.

CONCLUSION

There was a high prevalence of ECG-LVH and it is especially so with combining multiple criteria, hence the need for screening. Clinic-day hypertension was associated with ECG-LVH hence the need for diagnosing and aggressive treatment of hypertension in patients with diabetes mellitus.

A systematic review and meta-regression of temporal trends in the excess mortality associated with diabetes mellitus after myocardial infarction

BACKGROUND/OBJECTIVES

It is not well known whether the gap in outcomes after myocardial infarction (MI) between patients with and without diabetes mellitus (DM) has changed over time. We performed a systematic review and metaregression of temporal trends in the excess mortality associated with DM after MI.

METHODS

We searched the PubMed database for studies reporting mortality data according to diabetic status in patients hospitalized for MI or acute coronary syndromes (ACS). We included 139 studies/cohorts for analysis (432,066 diabetic patients and 1,182,108 nondiabetic patients).

RESULTS

When compared to their non-diabetic counterparts, patients with DM had an odds ratio (OR) [95% CI] of 1.66 [1.59-1.74] (P<0.0001) for early mortality, and of 1.86 [1.75-1.97] (P<0.0001) for 6-12months mortality. When all data from the 116 studies reporting early mortality were pooled, there was no significant relationship between calendar year and Log (OR). Likewise, when considering the 61 studies reporting 6-12months mortality, there was no significant relationship between calendar year and Log (OR). Similar to the overall pooled analysis, no significant relationship between inclusion year and Log (OR) for mortality in diabetic patients was observed in sensitivity analyses performed in studies with ST-elevation MI as inclusion criteria, in randomized trials, in studies including >2000 patients, and in studies with DM prevalence >20%.

CONCLUSIONS

We found no evidence for temporal changes in the incremental mortality risk associated with DM in the setting of MI. The improvements in management of MI patients during the last decades have not been associated with a reduction of the gap between diabetic and non-diabetic patients.

Atypical presentation of acute and chronic coronary artery disease in diabetics

In patients with diabetes mellitus, cardiovascular disease is the principal cause of mortality and chest pain is the most frequent symptom in patients with stable and acute coronary artery disease. However, there is little knowledge concerning the pervasiveness of uncommon presentations in diabetics. The symptomatology of acute coronary syndrome, which comprises both pain and non-pain symptoms, may be affected by traditional risk factors such as age, gender, smoking, hypertension, diabetes, and dyslipidemia. Such atypical symptoms may range from silent myocardial ischemia to a wide spectrum of non-chest pain symptoms. Worldwide, few studies have highlighted this under-investigated subject, and this aspect of ischemic heart disease has also been under-evaluated in the major clinical trials. The results of these studies are highly diverse which makes definitive conclusions regarding the spectrum of atypical presentation of acute and even stable chronic coronay artery disease difficult to confirm. This may have a significant impact on the morbidity and mortality of coronary artery disease in diabetics. In this up-to-date review we will try to analyze the most recent studies on the atypical presentations in both acute and chronic ischemic heart disease which may give some emphasis to this under-investigated topic.

Gender differences in the impact of diabetes on mortality in patients with established coronary artery disease: a report from the eastern Taiwan integrated health care delivery system of Coronary Heart Disease (ET-CHD) registry, 1997-2006

OBJECTIVES

The effect of type 2 diabetes mellitus (DM) on mortality was more pronounced in women than men with coronary artery disease (CAD) in the pre-stent era before 1996. However this relationship is controversial in the post-stent era.

METHODS

We studied a cohort of 1073 patients with angiographically defined CAD from the Eastern Taiwan integrated health care delivery system of Coronary Heart Disease (ET-CHD) registry during 1997-2003 in Tzu-Chi General Hospital, Hualien, Taiwan. To evaluate gender-specific DM effect on mortality, the subjects were divided into 4 groups: diabetic women (n=147), non-diabetic women (n=127), diabetic men (n=239), and non-diabetic men (n=560). At a mean follow-up of 5.4 years, cardiac and all-cause mortality were the primary end points.

RESULTS

Annual total mortality rates were 10.2%, 5.1%, 7.2%, and 4.8%; annual cardiac mortality rates were 8.2%, 3.0%, 4.3%, and 2.6% for diabetic women, non-diabetic women, diabetic men, and non-diabetic men, respectively. Multivariate Cox regression models, adjusted for possible confounders showed that gender-specific hazard ratios (HRs) of DM for total mortality were 2.02 (95% CI: 1.32-3.09), and 1.72 (95% CI: 1.32-2.25) for women and men, respectively. The HRs for total mortality associated with diabetes were not different between women and men (p=0.53). Similarly, adjusted gender-specific HRs of DM for cardiac mortality were 2.46 (95% CI: 1.45-4.19) for women, and 1.83 (95% CI: 1.28-2.62) for men, which were also not significantly different (p=0.36).

CONCLUSIONS

Among patients with CAD, the impact of DM on mortality was consistently higher in women than in men, but the differences across sexes were not statistically significant after 1996 in Taiwan.

Comparison of clinical outcomes following acute myocardial infarctions in hypertensive patients with or without diabetes

Background and Objectives

It is thought that patients with diabetes mellitus (DM) have a poor prognosis after an acute myocardial infarction (AMI), but the effect of diabetes on the outcomes of hypertensive patients with AMIs has not been elucidated in the Korean population. The aim of this study was to investigate the effects of diabetes on long-term clinical outcomes following AMIs in patients with hypertension.

Subjects and Methods

Using data from the Korea Acute Myocardial Infarction Registry (November 2005 to December 2006), 2,233 hypertensive patients with AMIs were grouped as follows based on the presence of DM: group I, diabetic hypertension (n=892, 544 men, mean age=66.2±10.9 years); and group II, non-diabetic hypertension (n=1341, 938 men, mean age=63.9±12.8 years). The primary study outcomes included in-hospital death and major adverse cardiac events (MACE; cardiac death, myocardial infarction (MI), repeat percutaneous coronary intervention, and coronary artery bypass surgery) at the 1 year follow-up.

Results

Hypertensive patients with DM were older and more likely to be women. The diabetic group had lower blood pressure (p<0.001), a lower left ventricular ejection fraction (p<0.001), a more severe degree of heart failure (p<0.001), a longer duration of coronary care unit admission (p<0.001), and a higher incidence of hyperlipidemia (p=0.007). The N-terminal pro-brain natriuretic peptide level (4602.5±8710.6 pg/mL vs. 2320.8±5837.9 pg/mL, p<0.001) was higher and the creatinine clearance (62.4±29.9 mL/min vs. 73.0±40.8 mL/min, p<0.001) was lower in the diabetic group than the non-diabetic group. Coronary angiographic findings revealed more frequent involvement of the left main stem (p=0.002) and multiple vessels (p<0.001) in the diabetic group. The rate of in-hospital death was higher in the diabetic group (p<0.001). During follow-up, the rates of composite MACE at 1 month, 6 months, and 12 months were higher in the diabetic group (p<0.001).

Conclusion

In hypertensive patients with AMI, DM was associated with worse clinical and angiographic features, with a higher risk of development of severe heart failure, and an increased risk of MACE on long-term clinical follow-up.

Cardiovascular disease in older women: a challenge in diagnosis and treatment

Cardiovascular disease is the leading cause of death in women and more heart disease is present in elderly women than men. Risk factors for heart disease affect men and women differently, with a greater impact of diabetes, hyperlipidemia and smoking in women. Diagnosis of heart disease can be more challenging in women, especially when elderly, as symptoms may be vague. Understanding the appropriate use of diagnostic testing and appropriate treatment is essential, given the high burden of disease in elderly women. This article will discuss the current guidelines for diagnosis and therapy of heart disease in women and will discuss the appropriate role of prevention strategies.

Characteristics and in-hospital mortality of diabetics and nondiabetics with an acute coronary syndrome; the GREECS study

OBJECTIVES

In this work, we sought to describe the baseline characteristics and the management of patients with and without diabetes hospitalized with acute coronary syndromes (ACS), as well as to assess the prognostic value of diabetes status to the severity of ACS and in-hospital mortality.

METHODS

A sample of six hospitals located in Greek urban and rural regions was selected and we recorded almost all admissions due to ACS, from October 2003 to September 2004. 2,172 patients were included in the study. Socio-demographic, clinical, dietary and other lifestyle characteristics was recorded.

RESULTS

Approximately 1 in 3 patients admitted at the hospital with ACS had history of diabetes. Diabetes mellitus was associated with old age, female gender and more prevalent history of coronary heart disease, hypertension and renal failure. Diabetics sought medical care later and they were less likely to receive fibrinolytic therapy. No statistically significant difference was observed on severity of ACS between diabetics and nondiabetics. The in-hospital mortality was higher in diabetics compared to nondiabetics. In a multivariate analysis only insulin-treated diabetics had an increased mortality rate compared to nondiabetics.

CONCLUSIONS

The use of more effective medications and interventions must be used in diabetics who develop ACS, as well as educational efforts should be directed to those patients for reducing the pre-hospital delay.

Prevalence of diabetes and other cardiovascular risk factors in an Iranian population with acute coronary syndrome

Background

Coronary artery disease is the leading cause of death in industrialized countries and most patients with diabetes die from complications of atherosclerosis. The objective of this study was to determine the presence of diabetes mellitus and other conventional coronary heart disease risk factors (cigarette smoking, hypertension and hyperlipidemia) in patients with acute coronary events in an Iranian population.

Methods

The study included 514 patients with unstable angina or myocardial infarction (MI) out of 720 patients admitted to CCU ward of a general hospital from March 2003 to March 2005. History of diabetes, hypertension and cigarette smoking, demographic indices, coronary heart disease and diabetes mellitus treatment, myocardial enzymes, serum triglycerides (TG) and cholesterol and fasting and non fasting blood glucose levels and HbA1C of diabetics were recorded of admission sheets. The data were structured to appropriate one way ANOVA, T tests, and chi square test with SPSS 13 product for windows.

Results

Out of all patients 35.8% were female, 30% were diabetics (Duration 13.4 ± 8.7 years), 42% were smoker and 91% were hypertensive. Twenty four percent had MI and 76% had unstable angina. MI was significantly higher in diabetic patients (36.4% vs. 19.2%, P < 0.001). Location and extension of MI and myocardial enzymes did not differ between diabetics and non-diabetic patients. Diabetic patients were older than non diabetics (65 ± 11.6 vs. 59.7 ± 12.5 years, p < 0.05). Five (66.7%) out of 9 patients with fatal MI were diabetics (Odds Ratio = 2.98). Age, duration of diabetes and HbA1c levels, did not differ between diabetic patients with or without MI. Hypertension and current smoking was significantly higher in patients with MI compared to patients with unstable angina (p < 0.05). Serum TG, HDL-C, LDL-C and total cholesterol level did not differ between patients with MI and unstable angina. Diabetic patients compare to non diabetic patients were more hypertensive (96% vs. 88.7%, p < 0.005) and had higher serum triglyceride (TG over 200 mg/dl, 35.1% vs. 26.4, p <0.05). Diabetes was more frequent among women than men (36.4% vs. 26.4%, p < 0.05). Women were older than men (65 ± 11.6 vs. 59.2 ± 13 years, p < 0.005) and had higher total serum cholesterol (200 ± 41.8 vs. 192 ± 42.5 mg/dl, p < 0.05) and HDL-C levels (49.7 ± 22 vs. 40 ± 13 mg/dl, p < 0.005). Ninety seven percent of all patients had at least one of cardiovascular risk factors (hypertension, smoking, diabetes, high cholesterol and low HDL-cholesterol levels).

Conclusion

In this study 19 out of 20 patients with acute coronary event have at least one of conventional cardiac risk factors. Diabetes and hypertension are leading risk factors, which may directly or indirectly interfere and predict more serious complications of coronary heart disease.

Favourable trends in the incidence and outcome of myocardial infarction in nondiabetic, but not in diabetic, subjects: findings from the MONICA myocardial infarction registry in northern Sweden in 1989-2000

BACKGROUND

The aim of this study was to compare time trends in incidence, case fatality and mortality due to myocardial infarction (MI) in patients with or without diabetes.

METHODS

This study was based on the Northern Sweden MONICA Project MI registry with a target population of about 200,000 inhabitants in the age group 35--64 years in the two northernmost counties of Sweden. During 1989--2000, 6254 patients who had had an MI according to MONICA criteria were included in this study: 4569 patients had a first MI and 1685 had a recurrent MI. Sixteen per cent of the men and 20% of the women had had diabetes mellitus diagnosed prior the MI.

RESULTS

Over the 12-year period, there was a declining trend in incidence and case fatality in first MI. Also, the event rates (first ever and recurrent MI) declined in men without diabetes. In women without diabetes favourable time trends were seen in first ever MI, recurrent MI and in case fatality. There were no favourable time trends for any of these outcomes in patients with diabetes.

CONCLUSION

In nondiabetic subjects below the age of 65, the incidence of, and case-fatality in, MI declined. This led to a decreased mortality over the 12-year period. These favourable trends over time were not observed in diabetic subjects.

Increased prevalence of left ventricular hypertrophy in hypertensive women with type 2 diabetes mellitus

BACKGROUND

Left ventricular hypertrophy (LVH) is a powerful independent risk factor for cardiovascular morbidity and mortality among hypertensive patients. Data regarding relationships between diabetes and LVH are controversial and inconclusive, whereas possible gender differences were not specifically investigated. The goal of this work was to investigate whether gender differences in left heart structure and mass are present in hypertensive patients with type 2 diabetes.

METHODS

Five hundred fifty hypertensive patients with at least one additional cardiovascular risk factor (314 men and 246 women, age 52 to 81, mean 66 +/- 6 years), were enrolled in the present analysis. In 200 (36%) of them--108 men and 92 women--type 2 diabetes mellitus was found upon enrollment. End-diastolic measurements of interventricular septal thickness (IVS), LV internal diameter, and posterior wall thickness were performed employing two-dimensionally guided M-mode echocardiograms. LVH was diagnosed when LV mass index (LVMI) was > 134 g/m2 in men and > 110 g/m2 in women.

RESULTS

Mean LVMI was significantly higher among diabetic vs. nondiabetic women (112.5 +/- 29 vs. 105.6 +/- 24, p = 0.03). In addition, diabetic women presented a significantly higher prevalence of increased IVS thickness, LVMI and left atrial diameter on intra-gender comparisons. The age adjusted relative risk for increased LVMI in diabetics vs. nondiabetics was 1.47 (95% CI: 1.0-2.2) in females and only 0.8 (0.5-1.3) in males.

CONCLUSION

Type 2 diabetes mellitus was associated with a significantly higher prevalence of LVH and left atrial enlargement in hypertensive women.

Sex differences in the prognostic importance of diabetes in patients with ischemic heart disease undergoing coronary angiography

OBJECTIVE

Women with ischemic heart disease have poorer outcomes than men and are suggested to have greater risk associated with diabetes. We evaluated the prognosis associated with diabetes, in analyses stratified by sex, to determine whether similar differences are seen in a large unselected cohort of patients.

RESEARCH DESIGN AND METHODS

Using the Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease (APPROACH), a clinical data collection and follow-up initiative capturing all patients undergoing cardiac catheterization in Alberta, Canada, the relative significance of diabetes on long-term survival in 13152 men and 4249 women was evaluated in patients presenting with or without myocardial infarction and according to first treatment received.

RESULTS

The 1-year mortality rates were 4.7% and 6.8% in men and women (P < 0.001), 4.1% and 7.4% in nondiabetic and diabetic men (P < 0.001), and 5.8% and 9.6% in nondiabetic and diabetic women, respectively (P < 0.001). The risk-adjusted Cox proportional hazard ratios associated with diabetes in myocardial infarction were 1.03 in men and 1.20 in women. The diabetes hazard ratios for percutaneous coronary intervention were 1.28 in men and 1.40 in women, 1.23 in men and 1.32 in women for bypass surgery, and 1.26 in men and 1.31 in women for medical therapy (P = NS for all diabetes hazard ratio comparisons between men and women).

CONCLUSIONS

Hazard ratios quantifying the adverse prognosis associated with diabetes in patients undergoing angiography are consistently higher among women than men, but the differences across sexes are not statistically significant. These slight sex differences noted in the APPROACH registry are similar to previously reported findings and may be clinically important.

Clinical profile of chronic heart failure in elderly women

The pathogenesis, clinical course, and treatment of chronic heart failure (HF) are different in elderly women from those of patients recruited in the landmark trials of chronic HF. Patients included in these landmark trials were predominantly men whose age was 10-15 years younger than the average age of patients with chronic HF in the United States. Diastolic dysfunction resulting in impaired left ventricular (LV) filling is the preponderant LV functional alteration that leads to chronic HF in elderly women. Gender differences in the LV remodeling process that accompanies chronic cardiac pressure are likely to be responsible for the preponderance of LV diastolic dysfunction over systolic dysfunction in elderly women. In response to chronic pressure overload, the LV wall becomes thicker in women than in men. Consequently, in response to chronic pressure overload, women are able to normalize LV wall stress and preserve LV systolic function to a greater extent than men. However, impaired LV filling is an undesirable consequence of the greater increase in LV wall thickness in women. Thus, clinical observations and therapeutic guidelines derived from data collected in the landmark trials of chronic HF may not apply to elderly women with chronic HF. In view of the lack of evidence-based information needed to guide the management of elderly women with chronic HF, special attention should be given to include a substantial number of elderly women in future therapeutic trials recruiting patients with chronic HF.

Use of thrombolytic therapy for acute myocardial infarction: effects of gender and age on treatment rates

BACKGROUND

Although there have been efforts to increase the utilization of thrombolytic therapy, there are still many patients who might benefit from this treatment who do not receive it. Women and the elderly have been particularly undertreated, despite evidence that their survival can be improved with thrombolysis. This study was undertaken to determine the relative rates of treatment of women vs. men and the elderly vs. younger subjects and to examine factors that might explain differences in treatment frequency.

METHODS AND RESULTS

This is a retrospective study of patients who presented to the Emergency Departments of four local hospitals in 1993 and 1994 with evidence for acute ST-elevation myocardial infarction. Demographic data, past medical history, information on co-morbid illnesses, and times to hospital arrival, first electrocardiogram, physician notification, and thrombolytic therapy were recorded as was survival to hospital discharge. Data for patients who did or did not receive thrombolytic therapy were compared. Men were treated more frequently in both tertiary and community hospitals. Women were older, but within each age bracket, men were treated more often. The time of arrival was similar for men and women, but men who arrived within 6 hours or 6-12 hours after pain onset were treated at a higher rate than women. For patients without contraindications, treatment was not affected by gender or age. However, treatment rates decreased with increased prevalence of exclusionary factors, and since both women and the elderly tended to have more such factors, elderly women were treated at a markedly lower rate. The single clinical factor that increased thrombolytic usage in women compared to men was a history of prior myocardial infarction.

CONCLUSION

Despite convincing evidence that thrombolytic therapy is beneficial in women and the elderly, these groups have been relatively neglected unless attention is called to clinical risk, for example, by history of prior myocardial infarction.

Impaired glucose metabolism predicts mortality after a myocardial infarction

Diabetes is a risk factor for increased mortality after a myocardial infarction. Whether this applies for patients with hyperglycemia during the acute phase of a acute myocardial infarction is unclear. Therefore we determined the relation between admission plasma glucose level and mortality in a prospectively collected series of 336 consecutive AMI patients. Patients were divided in four groups based on WHO criteria for glucose levels: I: <5.6 mmol/l, II: 5.6--8.3 mmol/l, III: 8.4--11.0 mmol/l, IV: 11.1 mmol/l. The average age was 68+/-11 years with a peak CK of 1378+/-160 U/l, 34% were anterior wall AMIs and 52% were treated with thrombolysis. All patients had a long-term follow-up control at an average of 14.2 months. One year mortality rate was 19.3% and rose to 44% in patients with glucose levels >11.1 mmol/l. The mortality was higher in diabetic patients than in non-diabetic patients (40 vs. 16%; P<0.05). Multivariate analysis revealed an independent effect of glucose level on mortality. In conclusions, our study in an unselected patient population demonstrates that admission plasma glucose level independently predicts 1 year mortality even in absence of diagnosed diabetes mellitus. Further studies evaluating the effect of acute insulin intervention in reducing mortality are warranted.