Angiographic severity and extent of coronary artery disease in patients with type 1 diabetes mellitus

Diabetic Vasculopathy: Molecular Mechanisms and Clinical Insights

Clinical and basic studies have documented that both hyperglycemia and insulin-resistance/hyperinsulinemia not only constitute metabolic disorders contributing to cardiometabolic syndrome, but also predispose to diabetic vasculopathy, which refers to diabetes-mellitus-induced microvascular and macrovascular complications, including retinopathy, neuropathy, atherosclerosis, coronary artery disease, hypertension, and peripheral artery disease. The underlying molecular and cellular mechanisms include inappropriate activation of the renin angiotensin-aldosterone system, mitochondrial dysfunction, excessive oxidative stress, inflammation, dyslipidemia, and thrombosis. These abnormalities collectively promote metabolic disorders and further promote diabetic vasculopathy. Recent evidence has revealed that endothelial progenitor cell dysfunction, gut dysbiosis, and the abnormal release of extracellular vesicles and their carried microRNAs also contribute to the development and progression of diabetic vasculopathy. Therefore, clinical control and treatment of diabetes mellitus, as well as the development of novel therapeutic strategies are crucial in preventing cardiometabolic syndrome and related diabetic vasculopathy. The present review focuses on the relationship between insulin resistance and diabetes mellitus in diabetic vasculopathy and related cardiovascular disease, highlighting epidemiology and clinical characteristics, pathophysiology, and molecular mechanisms, as well as management strategies.

Long-term cardiovascular prognosis of patients with type 1 diabetes after myocardial infarction

Background

To explore long-term cardiovascular prognosis after myocardial infarction (MI) among patients with type 1 diabetes.

Methods

Patients with type 1 diabetes surviving 90 days after MI (n = 1508; 60% male, mean age = 62.1 years) or without any type of diabetes (n = 62,785) in Finland during 2005–2018 were retrospectively studied using multiple national registries. The primary outcome of interest was a combined major adverse cardiovascular event (MACE; cardiovascular death, recurrent MI, ischemic stroke, or heart failure hospitalization) studied with a competing risk Fine-Gray analyses. Median follow-up was 3.9 years (maximum 12 years). Differences between groups were balanced by multivariable adjustments and propensity score matching (n = 1401 patient pairs).

Results

Cumulative incidence of MACE after MI was higher in patients with type 1 diabetes (67.6%) compared to propensity score-matched patients without diabetes (46.0%) (sub-distribution hazard ratio [sHR]: 1.94; 95% confidence interval [CI]: 1.74–2.17; p < 0.0001). Probabilities of cardiovascular death (sHR 1.81; p < 0.0001), recurrent MI (sHR 1.91; p < 0.0001), ischemic stroke (sHR 1.50; p = 0.0003), and heart failure hospitalization (sHR 1.98; p < 0.0001) were higher in patients with type 1 diabetes. Incidence of MACE was higher in diabetes patients than in controls in subgroups of men and women, patients aged < 60 and ≥ 60 years, revascularized and non-revascularized patients, and patients with and without atrial fibrillation, heart failure, or malignancy.

Conclusions

Patients with type 1 diabetes have notably poorer long-term cardiovascular prognosis after an MI compared to patients without diabetes. These results underline the importance of effective secondary prevention after MI in patients with type 1 diabetes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01608-3.

Case Fatality of Patients With Type 1 Diabetes After Myocardial Infarction

OBJECTIVE

Type 1 diabetes is a risk factor for myocardial infarction (MI). We aimed to evaluate the case fatality in patients with type 1 diabetes after MI.

RESEARCH DESIGN AND METHODS

Consecutive patients experiencing MI with type 1 diabetes (n = 1,935; 41% female; mean age 62.5 years) and without diabetes (n = 74,671) admitted to 20 hospitals in Finland from 2005 to 2018 were studied using national registries. The outcome of interest was death within 1 year after MI. Differences between groups were balanced by multivariable adjustments and propensity score matching.

RESULTS

Case fatality was higher in patients with type 1 diabetes than in propensity score-matched controls without diabetes at 30 days (12.8% vs. 8.5%) and at 1 year (24.3% vs. 16.8%) after MI (hazard ratio 1.55; 95% CI 1.32-1.81; P < 0.0001). Patients with type 1 diabetes had poorer prognosis in subgroups of men and women and of those with and without ST-elevation MI, with and without revascularization, with and without atrial fibrillation, and with and without heart failure. The relative fatality risk in type 1 diabetes was highest in younger patients. Older age, heart failure, peripheral vascular disease, renal failure, and no revascularization were associated with worse prognosis after MI. The case fatality among patients with type 1 diabetes decreased during the study period, but outcome differences compared with patients without diabetes remained similar.

CONCLUSIONS

Patients with type 1 diabetes are at higher risk of death after MI than patients without diabetes. Our findings call for attention to vigorous cardiovascular disease prevention in patients with type 1 diabetes.

Uncovering Cardiac Involvement in Childhood Diabetes: Is it Time to Move Toward Speckle Tracking Echocardiography in Childhood Diabetes Management?

Context:

One of the most common endocrine disorders in children is diabetes which is the leading cause of premature cardiovascular disease in adulthood.

Aims:

This study is aimed to investigate the extend of cardiac involvement in diabetic children by speckle tracking echocardiography (STE) in comparison to two-dimensional (2D) echocardiography and routine laboratory data.

Settings and Design:

A cross-sectional study conducted on patients under 18 years of age who deal with type one diabetes mellitus for more than 5 years.

Subjects and Methods:

To compare the STE results, we included the STE data of 25 normal age-matched children. All patients underwent laboratory analysis for lipid profile, blood sugar, and 2D echocardiography plus STE.

Statistical Analysis Used:

Two-sample independent t-test, Chi-square test, logistic regression test, Spearman's rank correlation coefficient, and the Pearson correlation coefficient.

Results:

From March 2018 to 2019, we included 53 patients, mean age 15.8 ± 0.39 years and 52.8% female, and 25 nondiabetic control in this study. STE revealed global longitudinal strain (LS) −18.4 versus − 24.2 for patient (44 valid cases) versus control group, respectively, with significant statistical difference. Diabetic patients had lower LS in all segments compared to the control group.

Conclusions:

STE has very high sensitivity to detect cardiac involvement far earlier than 2D echocardiography. None of the routine biomarkers or demographic features can predict cardiac involvement based on segmental abnormalities of STE. Active investigation to clear the remote impact of STE abnormalities and its practical role in childhood diabetes management is highly recommended.

Diabetic cardiomyopathy: Pathophysiology, theories and evidence to date

The prevalence of type 2 diabetes (T2D) has increased worldwide and doubled over the last two decades. It features among the top 10 causes of mortality and morbidity in the world. Cardiovascular disease is the leading cause of complications in diabetes and within this, heart failure has been shown to be the leading cause of emergency admissions in the United Kingdom. There are many hypotheses and well-evidenced mechanisms by which diabetic cardiomyopathy as an entity develops. This review aims to give an overview of these mechanisms, with particular emphasis on metabolic inflexibility. T2D is associated with inefficient substrate utilisation, an inability to increase glucose metabolism and dependence on fatty acid oxidation within the diabetic heart resulting in mitochondrial uncoupling, glucotoxicity, lipotoxicity and initially subclinical cardiac dysfunction and finally in overt heart failure. The review also gives a concise update on developments within clinical imaging, specifically cardiac magnetic resonance studies to characterise and phenotype early cardiac dysfunction in T2D. A better understanding of the pathophysiology involved provides a platform for targeted therapy in diabetes to prevent the development of early heart failure with preserved ejection fraction.

Effect of early glycemic control on HbA1c tracking and development of vascular complications after 5 years of childhood onset type 1 diabetes: Systematic review and meta-analysis

OBJECTIVE

A systematic review and meta-analysis was conducted to investigate if glycemic control measured by glycated hemoglobin (HbA1c) levels near diagnosis are predictive of future glycemic outcomes and vascular complications in childhood onset type 1 diabetes (T1D).

METHODS

Evidence was gathered using electronic databases (MEDLINE, EMBASE, Web of Science, CINAHL, Scopus, and Cochrane Library up to February 2017) and snowballing techniques. Studies investigating the association between the exposure "early glycemic control" and main outcome: "tracking of early control" and secondary outcome: risk of future complications; in children and young people aged 0 to 19 years at baseline; were systematically double-reviewed, quality assessed, and outcome data extracted for synthesis and meta-analysis.

FINDINGS

Five studies (N = 4227 participants) were eligible. HbA1c levels were sub-optimal throughout the study period but tended to stabilize in a "track" by 6 months after T1D diagnosis. The group with low HbA1c <53 mmol/mol (<7%) at baseline had lower long-term HbA1c levels than the higher HbA1c group. The estimated standardized mean difference between the sub groups showed a reduction of HbA1c levels on average by 1.6% (range -0.95% to -2.28%) from baseline. Only one study investigated the association between early glycemic control and development of vascular complications in childhood onset T1D.

INTERPRETATIONS

Glycemic control after the first few months of childhood onset T1D, remains stable but sub-optimal for a decade. The low and high HbA1c levels at baseline seem to "track" in their respective tracks during the 10-year follow-up, however, the initial difference between groups narrows over time.

PROSPERO

CRD42015024546 http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42015024546.

The early detection of atherosclerosis in type 1 diabetes: why, how and what to do about it

The major cause of morbidity and often premature mortality in people with type I diabetes (T1D) is cardiovascular disease owing to accelerated atherosclerosis. We review publications relating to the rationale behind, and clinical tests for, detecting and treating early atherosclerosis in people with T1D. Currently available tools for atherosclerosis assessment include risk equations using vascular risk factors, arterial intima-media thickness, the ankle-brachial index, coronary artery calcification and angiography, and for more advanced lesions, intravascular ultrasound and optical coherence tomography. Evolving research tools include risk equations incorporating novel clinical, biochemical and molecular tests; vascular MRI and molecular imaging. As yet there is little information available to quantify early atherosclerosis. With better means to control the vascular risk factors, such as hypertension, dyslipidaemia and glycaemic control, and emerging therapies to control novel risk factors, further epidemiologic and clinical trials are merited to facilitate the translation into clinical practice of robust means to detect, monitor and treat early atherosclerosis in those with T1D.

Atherosclerosis and Microvascular Complications: Results From the Canadian Study of Longevity in Type 1 Diabetes

OBJECTIVE

Type 1 diabetes carries a significant risk for cardiovascular mortality, but it is unclear how atherosclerosis associates with microvascular complications. We aimed to determine the relationships between atherosclerotic burden and neuropathy, retinopathy, and diabetic kidney disease (DKD) in adults with a ≥50-year history of type 1 diabetes.

RESEARCH DESIGN AND METHODS

Adults with type 1 diabetes (n = 69) underwent coronary artery calcification (CAC) volume scoring by wide-volume computerized tomography. Microvascular complications were graded as follows: neuropathy by clinical assessment, electrophysiology, vibration and cooling detection thresholds, heart rate variability, and corneal confocal microscopy; retinopathy by ultra-wide-field retinal imaging; and DKD by renal hemodynamic function measured by inulin and para-aminohippurate clearance at baseline and after intravenous infusion of angiotensin II. The cohort was dichotomized to high (≥300 Agatston units [AU]) or low (<300 AU) CAC and was stratified by diabetes status. A comparator group without diabetes (n = 73) matched for age and sex also underwent all study procedures except for retinal imaging.

RESULTS

CAC scores were higher in participants with type 1 diabetes (median Agatston score 1,000 [interquartile range = 222, 2,373] AU vs. 1 [0.75] AU in comparators, P < 0.001). In participants with type 1 diabetes, high CAC scores associated with markers of neuropathy and retinopathy, but not with DKD, or renal hemodynamic function at baseline or in response to angiotensin II.

CONCLUSIONS

The presence of high CAC in adults with longstanding type 1 diabetes was associated with large nerve fiber neuropathy and retinopathy but not with renal hemodynamic function, suggesting that neuropathy, retinopathy, and macrovascular calcification share common risk factors.

Mitochondrial regulation of diabetic vascular disease: an emerging opportunity

Diabetes-related vascular complication rates remain unacceptably high despite guideline-based medical therapies that are significantly more effective in individuals without diabetes. This critical gap represents an opportunity for researchers and clinicians to collaborate on targeting mechanisms and pathways that specifically contribute to vascular pathology in patients with diabetes mellitus. Dysfunctional mitochondria producing excessive mitochondrial reactive oxygen species (mtROS) play a proximal cell-signaling role in the development of vascular endothelial dysfunction in the setting of diabetes. Targeting the mechanisms of production of mtROS or mtROS themselves represents an attractive method to reduce the prevalence and severity of diabetic vascular disease. This review focuses on the role of mitochondria in the development of diabetic vascular disease and current developments in methods to improve mitochondrial health to improve vascular outcomes in patients with DM.

Characteristics and Prognosis in Women and Men With Type 1 Diabetes Undergoing Coronary Angiography: A Nationwide Registry Report

OBJECTIVE

To describe sex aspects on extent of coronary artery disease (CAD) and prognosis in a contemporary population with type 1 diabetes.

RESEARCH DESIGN AND METHODS

All patients undergoing coronary angiography, 2001-2013, included in the Swedish Coronary Angiography and Angioplasty Registry and the Swedish National Diabetes Register as type 1 diabetes were followed for mortality until 31 December 2013. The coronary angiogram was classified into normal, one-vessel disease, two-vessel disease, three-vessel disease, and left main stem disease.

RESULTS

In all, 2,776 patients (42% women) with mean age 58 years (SD 11) were followed for 7.2 years (SD 2.2). Diabetes duration was longer in women (37 ± 14 vs. 34 ± 14 years in men; P < 0.001), who also had more retinopathy (68% vs. 65%; P = 0.050), whereas microalbuminuria was less common (41% vs. 51%; P < 0.001). Indications for coronary angiography did not substantially differ in women and men. The extent of CAD was somewhat less severe in women (normal angiogram 23.5% vs. 19.1%, three-vessel and left main stem disease 34.5% vs. 40.4%; P = 0.002), whereas mortality did not differ (adjusted hazard ratio 1.03 [95% CI 0.88-1.20]; P = 0.754). The standard mortality ratio for women the first year was 7.49 (5.73-9.62) and for men was 4.58 (3.60-5.74).

CONCLUSIONS

In patients with type 1 diabetes admitted for coronary angiography, the extent of CAD was almost similar in women and men, and total long-term mortality did not differ. Type 1 diabetes was associated with higher mortality risk in women than in men when compared with the general population. These data support that type 1 diabetes attenuates the cardiovascular risk difference seen in men and women in the general population.

Intensive Diabetes Treatment and Cardiovascular Outcomes in Type 1 Diabetes Mellitus: Implications of the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications Study 30-Year Follow-up

Type 1 diabetes mellitus, an autoimmune disorder characterized by beta-cell destruction and absolute insulin deficiency, is associated with significantly increased cardiovascular disease risk but the mechanisms underlying this enhanced risk are unclear. Results of the pivotal Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications study have shown that compared to conventional therapy, intensive glycemic control results in decreased cardiovascular morbidity and mortality. Evidence from this study also revealed contributions of blood pressure, renal disease, body weight, and lipids to cardiovascular disease in type 1 diabetes mellitus. Extrapolating from existing evidence, this article addresses clinical strategies to mitigate cardiovascular risks.

Stent fracture is associated with a higher mortality in patients with type-2 diabetes treated by implantation of a second-generation drug-eluting stent

Type 2 diabetes correlates with clinical events after the implantation of a second-generation drug-eluting stent (DES). The rate and prognostic value of stent fracture (SF) in patients with diabetes who underwent DES implantation remain unknown. A total of 1160 patients with- and 2251 without- diabetes, who underwent surveillance angiography at 1 year after DES implantation between June 2004 and August 2014, were prospectively studied. The primary endpoints included the incidence of SF and a composite major adverse cardiac event [MACE, including myocardial infarction (MI), cardiac death, and target-vessel revascularization (TVR)] at 1-year follow-up and at the end of follow-up for overall patients, and target lesion failure [TLF, including cardiac death, target vessel myocardial infarction (TVMI) and target lesion revascularization (TLR)] at the end of study for SF patients. In general, diabetes was associated with a higher rate of MACE at 1-year (18.4 vs. 12.9%) and end of follow-up (24.0 vs. 18.6%, all p < 0.001), compared with those in patients who did not have diabetes. The 1-year SF rate was comparable among patients with diabetes (n = 153, 13.2%) and non-diabetic patients (n = 273, 12.1%, p > 0.05). Diabetic patients with SF had a 2.6-fold increase of SF-related cardiac death at the end of study and threefold increase of re-repeat TLR when compared with non-diabetic patients with SF (5.9 vs. 2.2%, p = 0.040; 6.5 vs. 2.2%, p = 0.032), respectively. Given the fact that diabetes is correlated with increased MACE rate, SF in diabetic patients translates into differences in mortality and re-repeat TLR compared with the non-diabetic group.

Mortality and extent of coronary artery disease in 2776 patients with type 1 diabetes undergoing coronary angiography: A nationwide study

Background In a modern perspective there is limited information on mortality by affected coronary vessels assessed by coronary angiography in patients with type 1 diabetes. The aim of the present study was to characterise distribution of coronary artery disease and impact on long-term mortality in patients with type 1 diabetes undergoing coronary angiography. Design The design of this research was a nationwide population-based cohort study. Methods Individuals ( n = 2776) with type 1 diabetes undergoing coronary angiography 2001-2013 included in the Swedish National Diabetes Registry and Swedish Coronary Angiography and Angioplasty Registry were followed for mortality until 31 December 2013 (mean 7.1 years). In 79% the indication was stable or acute coronary artery disease. Coronary artery disease was categorised into normal (21%), one- (23%), two- (18%), three- (29%) and left main-vessel disease (8%). Results Mean age was 57 years and 58% were male. Mean diabetes duration was 35 years, glycated haemoglobin was 67 mmol/mol and 44% had normal or one-vessel disease. In multivariate Cox proportional analyses hazard ratio for mortality compared with normal findings was 1.09 (95% confidence interval 0.80-1.48) for one, 1.43 (1.05-1.94) for two, 1.47 (1.10-1.96) for three and 1.90 (1.35-2.68) for left main-vessel disease. Renal failure 2.29 (1.77-2.96) and previous heart failure 1.76 (1.46-2.13) were highly associated with mortality. Standard mortality ratio the first year was 5.55 (4.65-6.56) and decreased to 2.80 (2.18-3.54) after five years. Conclusions In patients with type 1 diabetes referred for coronary angiography mortality is influenced by numbers of affected coronary vessels. The overall mortality rate was higher compared with the general population. These results support early intensive prevention of coronary artery disease in this population.

Bone Microarchitecture in Type 1 Diabetes: It Is Complicated

Patients with type 1 diabetes (T1DM) experience a disproportionate number of fractures for their bone mineral density (BMD). Differences in bone microarchitecture from those without the disease are thought to be responsible. However, the literature is inconclusive. New studies of the microarchitecture using three-dimensional imaging have the advantage of providing in vivo estimates of "bone quality," rather than examining areal BMD alone. There are drawbacks in that most studies have been done on those with less than a 30-year duration of T1DM, and the techniques used to measure vary as do the sites assessed. In addition to the rise in these imaging techniques, very recent literature presents evidence of an intimate relationship between skeletal health and vascular complications in T1DM. The following review provides an overview of the available studies of the bone microarchitecture in T1DM with a discussion of the burgeoning field of complications and skeletal health.

Diseases and Aging: Gender Matters

At first glance, biological differences between male and female sex seem obvious, but, in fact, they affect a vast number of deeper levels apart from reproductive function and related physiological features. Such differences affect all organizational levels including features of cell physiology and even functioning of separate organelles, which, among other things, account for such global processes as resistance to diseases and aging. Understanding of mechanisms underlying resistance of one of the sexes to pathological processes and aging will allow taking into consideration gender differences while developing drugs and therapeutic approaches, and it will provide an opportunity to reproduce and enhance such resistance in the more vulnerable gender. Here we review physiological as well as cellular and biological features of disease course including aging that are affected by gender and discuss potential mechanisms behind these processes. Such mechanisms include features of oxidative metabolism and mitochondrial functioning.

Cardiovascular disease and type 1 diabetes: prevalence, prediction and management in an ageing population

Cardiovascular disease (CVD) is a major cause of mortality in type 1 diabetes mellitus (T1D). However, evidence of its risks and management is often extrapolated from studies in type 2 diabetic (T2D) patients or the general population. This approach is unsatisfactory given that the underlying pathology, demographics and natural history of the disease differ between T1D and T2D. Furthermore, with a rising life expectancy, a greater number of T1D patients are exposed to the cardiovascular (CV) risk factors associated with an ageing population. The aim of this review is to examine the existing literature around CVD in T1D. We pay particular attention to CVD prevalence, how well we manage risk, potential biomarkers, and whether the studies included the older aged patients (defined as aged over 65). We also discuss approaches to the management of CV risk in the older aged. The available data suggest a significant CVD burden in patients with T1D and poor management of CV risk factors. This is underpinned by a poor evidence base for therapeutic management of CV risk specifically for patients with T1D, and in the most relevant population - the older aged patients. We would suggest that important areas remain to be addressed, particularly exploring the risks and benefits of therapeutic approaches to CVD management in the older aged.

Increased prevalence of psoriasis in patients with coronary artery disease: results from a case-control study

BACKGROUND

The incidence of myocardial events has been reported to be increased in patients with psoriasis.

OBJECTIVES

To investigate whether psoriasis is an independent risk factor for coronary artery disease (CAD).

METHODS

We compared the prevalence of psoriasis between case patients with a diagnosis of CAD based on coronary angiography findings and control patients with no CAD referred to the emergency surgery department for an acute noncardiovascular condition. Case and control patients were examined for the presence of psoriasis by two dermatologists. The prevalence of psoriasis was compared among patients with CAD according to CAD severity. Five-hundred cases and 500 age- and sex-matched controls were included.

RESULTS

Using matched univariate analysis, the prevalence of psoriasis was about twofold higher in CAD case patients than in control patients [8·0% vs. 3·4%, odds ratio (OR) 2·64; 95% confidence interval (CI) 1·42-4·88]. Using unconditional multivariate analysis, the association of psoriasis with CAD appeared to be borderline significant (OR 1·84; 95% CI 0·99-3·40). Psoriasis in patients with CAD was significantly associated with three-vessel involvement relative to one-or two-vessel involvement (13·1% vs. 6·1%; OR 3·07; 95% CI 1·50-6·25).

CONCLUSIONS

The prevalence of psoriasis is twofold higher in patients with CAD than in control patients without CAD. It is associated with a more severe coronary artery involvement.

Epicardial coronary arteries in khat chewers presenting with myocardial infarction

Background. Khat chewing is a common habit in Yemen despite increased evidence of its negative impact on the cardiovascular system. Aims. We aimed to study the epicardial coronary arteries in khat chewers presenting with myocardial infarction (AMI). Materials and Methods. A descriptive, cross-sectional study was conducted between November 2008 and May 2009 in Yemen. AMI patients who underwent coronary angiogram were enrolled and divided into groups (gp): gp1 (diabetic and khat chewers), gp2 (khat chewers and nondiabetic), and gp3 (diabetic and non-khat users). Results. Of 347 AMI patients 63%, 21%, and 16% were in gp 2, 3, and 1, respectively. Khat chewers were younger in comparison to non-khat users. Group 3 patients were more likely to have multivessel disease, severe left anterior descending (LAD), right coronary artery (RCA) stenosis and total RCA, and left circumflex (Lcx) occlusion compared to other groups. Group 1 patients were more likely to have total LAD occlusion and severe Lcx lesions. In multivariate analysis, age, diabetes mellitus, and smoking were significant independent predictors for significant coronary artery lesions; however, khat chewing did not show such association. Conclusions. Coronary spasm is the main mechanism of AMI in khat chewers. The impact of our finding for risk stratification and management warrants further studies.

The impact of cardiovascular risk factors on the site and extent of coronary artery disease

BACKGROUND

In patients with coronary artery disease (CAD), the site and extent of coronary artery involvement in terms of proximal versus distal stenosis and multi- versus single-vessel disease have a crucial effect on patients' outcome. This study was designed to evaluate the relationship between cardiovascular risk factors and the site and extent of coronary artery involvement.

METHODS

In this study of patients who had undergone coronary angiography in our hospital, 125 with proximal lesions were enrolled as the case group (group 1) and an equal age- and gender-matched number of patients with non-proximal lesions were selected as the control group (group 2). The two groups were compared based on the presence or absence of diabetes mellitus (DM), hypercholesterolaemia, hypertriglyceridaemia, hypertension (HTN) and cigarette smoking.

RESULTS

The frequency of DM was 33.6 and 10.4% in the case and control groups, respectively, which was statistically significant (p < 0.0001). However, the frequency of hypercholesterolaemia in the case and control groups was 30.4 and 29.6% (p = 0.89), respectively; for hypertriglyceridaemia it was 19.2 and 16.8% (p = 0.062), respectively; for HTN it was 33.6 and 28.8% (p = 0.4), respectively; and for cigarette smoking it was 28.8 and 39.2% (p = 0.08), respectively, which were not statistically significant. Diabetic patients compared to non-diabetics had more multi-vessel disease (89.1 vs 61%, p < 0.0001, respectively), which was statistically significant. There was no relationship between hypercholesterolaemia, hypertriglyceridaemia, HTN and cigarette smoking and extent (multi-vessel involvement) of CAD (p = NS).

CONCLUSION

Proximal and multi-vessel involvement of the coronary arteries in patients with CAD was related to a history of DM but not of hypercholesterolaemia, HTN, cigarette smoking and hypertiglyceridaemia.

Is it time to screen for the haptoglobin genotype to assess the cardiovascular risk profile and vitamin E therapy responsiveness in patients with diabetes?

Diabetes mellitus (DM) carries an increased risk for cardiovascular complications. Haptoglobin (Hp) is an abundant plasma protein with an antioxidant function by virtue of its ability to block the oxidative activity of extracorpuscular hemoglobin. There exist two common functional alleles at the Hp genetic locus, denoted 1 and 2, with three Hp genotypes (Hp 1-1, 2-1, and 2-2). The Hp protein expressed in Hp 2-2 individuals is markedly inferior in protecting against hemoglobin-induced oxidative stress. Hp 2-2 DM individuals have been shown to be at increased risk for the development of diabetes complications, particularly diabetic cardiovascular disease (CVD). We review the biological mechanisms underlying the interaction between the Hp genotype and DM on CVD and the accumulating evidence in favor of Hp genotyping all individuals with DM and providing antioxidant vitamin E supplementation specifically to Hp 2-2 DM individuals to reduce their CVD morbidity and mortality.

An intravascular ultrasound appraisal of atherosclerotic plaque distribution in diseased coronary arteries

BACKGROUND

The assumption that atherosclerosis accumulates in the proximal coronary arteries and that distal segments are spared has yet to be systematically shown in vivo.

METHODS

We used intravascular ultrasound to analyze complete proximal, mid, and distal segments from 75 diseased left anterior descending arteries (LADs) and 61 diseased right coronary arteries (RCAs) (including either the posterolateral [PLA; n = 38] or posterior descending artery [PDA; n = 23]) to document that distal coronary arteries are more often free of disease vs proximal vessels. External elastic membrane, lumen, and plaque and media areas were measured every 0.4 mm (median), and plaque burden (plaque and media/external elastic membrane) and percentage of normal (plaque and media thickness <0.3 mm) cross sections/segment were determined.

RESULTS

Left anterior descending artery plaque was heaviest in proximal and mid segments, diminishing significantly in distal segments; plaque burden was 46% ± 9% in proximal, 39% ± 8% in mid, and 31% ± 9% in distal LAD (P < .0001), with 93% (median) of distal LAD cross sections being normal compared with 21% of mid and 0% of proximal cross sections (P < .0001). Right coronary artery plaque gradient was less pronounced vs the LAD; plaque burden was 37% ± 13% in proximal, 40% ± 10% in mid, and 36% ± 10% in distal RCA, followed by 31% ± 11% in PDA and 33% ± 10% in PLA. This was supported by the median percentage of normal cross sections/segment: 0% proximal, 0% mid, and 23% distal RCA sections plus 100% PDA and 48% PLA sections.

CONCLUSIONS

Intravascular ultrasound data indicated a proximal-to-distal LAD plaque gradient; significant disease was uncommon in the distal LAD. Conversely, the proximal-to-distal RCA plaque gradient was less distinct than the LAD, although disease in the PDA was still reduced compared with proximal segments.

Hyperglycemia and endothelial dysfunction in atherosclerosis: lessons from type 1 diabetes

A clear relationship between diabetes and cardiovascular disease has been established for decades. Despite this, the mechanisms by which diabetes contributes to plaque formation remain in question. Some of this confusion derives from studies in type 2 diabetics where multiple components of metabolic syndrome show proatherosclerotic effects independent of underlying diabetes. However, the hyperglycemia that defines the diabetic condition independently affects atherogenesis in cell culture systems, animal models, and human patients. Endothelial cell biology plays a central role in atherosclerotic plaque formation regulating vessel permeability, inflammation, and thrombosis. The current paper highlights the mechanisms by which hyperglycemia affects endothelial cell biology to promote plaque formation.

Relation of coronary artery plaque location to extent of coronary artery disease studied by computed tomographic angiography

BACKGROUND

Distal coronary artery disease (CAD) is less amenable to surgery or stenting compared with proximal disease. However, little is known about the epidemiology of distal versus proximal CAD.

METHODS

We determined the prevalence and factors associated with proximal, mid, and distally located plaque in the left anterior descending, left circumflex, and right coronary arteries in 418 subjects without prior CAD history who underwent coronary computed tomographic angiography for symptoms or stress test results. Clinical characteristics and coronary artery calcium (CAC) scores were also determined.

RESULTS

Most subjects (88%) had plaque, but only 18% of plaques were associated with stenosis >50%. In subjects with single-vessel plaque, only 7% had distal plaque, whereas 75% had proximal plaque. With 3-vessel plaque, 70% had distal and 100% had proximal plaques. Of subjects with a single location of plaque along a vessel, most had proximal plaque (69%); isolated distal-vessel plaque was rare (2%). Distal plaque was dominantly found in association with both proximal and mid plaque (88%). After multivariable adjustment for demographics, traditional, and nontraditional risk factors, both increasing number of vessels with plaque and clinically significant CAC scores were independently associated with higher odds of distal plaque, whereas associations of traditional risk factors were weaker. Distal plaque was independently associated with stenosis > 50%.

CONCLUSION

These data support the concept that early lesions are most often proximal and that CAC scoring may be a poor screening tool for detecting proximal disease. Furthermore, distal lesions are more associated with advanced disease than with traditional cardiovascular risk factors.

Differences in atherosclerotic plaque burden and morphology between type 1 and 2 diabetes as assessed by multislice computed tomography

OBJECTIVE It is unclear whether the coronary atherosclerotic plaque burden is similar in patients with type 1 and type 2 diabetes. By using multislice computed tomography (MSCT), the presence, degree, and morphology of coronary artery disease (CAD) in patients with type 1 and type 2 diabetes were compared. RESEARCH DESIGN AND METHODS Prospectively, coronary artery calcium (CAC) scoring and MSCT coronary angiography were performed in 135 asymptomatic patients (65 patients with type 1 diabetes and 70 patients with type 2 diabetes). The presence and extent of coronary atherosclerosis as well as plaque phenotype were assessed and compared between groups. RESULTS No difference was observed in average CAC score (217 +/- 530 vs. 174 +/- 361) or in the prevalence of coronary atherosclerosis (65% vs. 71%) in patients with type 1 and type 2 diabetes. However, the prevalence of obstructive atherosclerosis was higher in patients with type 2 diabetes (n = 24; 34%) compared with that in patients with type 1 diabetes (n = 11; 17%) (P = 0.02). In addition, a higher mean number of atherosclerotic and obstructive plaques was observed in patients with type 2 diabetes. In addition, the percentage of noncalcified plaques was higher in patients with type 2 (66%) versus type 1 diabetes (27%) (P < 0.001), resulting in a higher plaque burden for each CAC score compared with that in type 1 diabetic patients. CONCLUSIONS Although CAC scores and the prevalence of coronary atherosclerosis were similar between patients with type 1 and type 2 diabetes, CAD was more extensive in the latter. Also, a relatively higher proportion of noncalcified plaques was observed in patients with type 2 diabetes. These observations may be valuable in the development of targeted management strategies adapted to diabetes type.

Type 1 diabetes, hyperglycaemia, and the heart

Type 1 diabetes is associated with a substantially increased risk of cardiovascular disease that might not always be appreciated in view of the fairly young age of patients with this condition. In fact, in type 1 diabetes, the heart is subject to a variety of pathological insults, including accelerated atherosclerosis, cardiac autonomic neuropathy, and possibly intrinsic cardiomyopathy. Although the relation between hyperglycaemia and microvascular complications has been well established, a direct effect of hyperglycaemia on cardiovascular disease in type 1 diabetes has long been debated. More recently, several studies, most notably the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications, have clarified this issue and provided conclusive evidence that hyperglycaemia is indeed a mediator of cardiovascular risk in type 1 diabetes and that intensive diabetes therapy can reduce cardiovascular disease outcomes. We review current concepts in type 1 diabetes and the heart, focusing on recent insights into the central role of hyperglycaemia.

Volumetric intravascular ultrasound imaging to illustrate the extent of coronary plaque burden in type 2 diabetic patients

BACKGROUND

Although angiography is the gold standard for coronary imaging, its efficacy in outlining diffuse coronary atherosclerosis in diabetic patients remains questionable. We aimed to compare quantitative cineangiographic analysis (QCA) with three-dimensional intravascular ultrasound (IVUS) imaging in type 2 diabetic patients with coronary artery disease.

METHODS

IVUS runs of 104 significant coronary lesions in 88 diabetic patients were performed. Arterial remodeling index was calculated as vessel area at minimal lumen area divided by mean reference vessel area.

RESULTS

No difference between the two analysis modes was shown for lesion length and minimal lumen diameter, whereas a significant discrepancy between QCA and IVUS was found for diameter stenosis (10 +/- 9% vs. 41 +/- 8%; P<.001) and vessel diameter (3.01 +/- 0.66 vs. 4.53 +/- 0.70 mm; P<.001). A significant difference on arterial remodeling at lesion site was found between insulin-treated diabetic patients and non-insulin-treated diabetic patients (remodeling index: 0.98 +/- 0.16 vs. 1.07 +/- 0.21; P=.04).

CONCLUSIONS

Coronary angiographic diagnosis in diabetic patients may be distorted due to a large plaque burden over longer vessel segments and the resulting absence of plaque-free reference segments. This distortion was found to be more pronounced in QCA analysis requiring a reference diameter, whereas volumetric IVUS imaging illustrated coronary artery dimensions more accurately according to anatomic structures. Constrictive arterial remodeling was observed more frequently in type 2 diabetic patients treated with insulin.

Large and Small Vessels Atherosclerosis: Similarities and Differences

Atherosclerosis is a systemic, multifocal disease leading to a various symptoms and clinical events. Beyond disparities related to the organs involved, some differences might exist according to whether the lesions occur in the large (proximal) or small (distal) arteries. Atherosclerotic lesions occur predominantly in the large vessels first, and more distal lesions occur with aging. Proximal lesions are usually more evolving, especially with higher rates of unstable plaques in the proximal segments of coronary arteries. Racial differences regarding lesion distribution exist, with higher rates of distal lesions observed in races other than caucaians. Despite conflicting results found in each vascular territory, there is a suggestion of a stronger association between large vessel disease and smoking and dyslipidemia, whereas diabetes appears more specific for small vessel disease. Hypertension is more frequently reported in intracranial than in extracranial cerebrovascular disease. Preliminary studies report inflammatory markers preferably associated to large-vessel atherosclerosis. Proximal lesions in 1 territory are more frequently associated with concomitant lesions in other territories. Geometric, hemodynamic, and histologic particularities in large and small vessels may at least partially explain these differences, and some recent data point out different biologic properties of the endothelium according to its location.

Comparative predictive and diagnostic value of flow-mediated vasodilation in the brachial artery and intima media thickness of the carotid artery for assessment of coronary artery disease severity

BACKGROUND

While recent reports suggest that both flow-mediated vasodilation (FMD) in the brachial artery (BA), endothelium-dependent vasodilatation, and intima media thickness (IMT) in the carotid artery correlate with the extent of coronary artery disease (CAD), it is not clear which modality is a better predictor for CAD severity and whether either of these modalities are superior to conventional ST-segment depression in exercise stress electrocardiogram (ECG). Thus, the goal of the present study was to compare the predictive value of FMD and IMT for CAD severity and to evaluate the diagnostic accuracy.

STUDY

A total of 103 consecutive patients (62+/-9 years, 79 men) with clinically suspected CAD underwent FMD and nitroglycerin-induced dilation (NTG-D) in the BA as well as measurement of carotid artery IMT by using high-resolution ultrasound, and exercise treadmill testing. Coronary stenosis index (CSI) was calculated from coronary angiography.

RESULTS

Seventy-three patients had significant CAD, and 30 patients showed no CAD (NL). FMD was significantly lower and IMT was significantly higher in patients with CAD compared with NL patients (FMD, 3.7+/-3.0% vs. 7.5+/-2.9%; IMT, 1.1+/-0.2 mm vs. 0.7+/-0.1 mm). FMD and IMT correlated to CSI to a similar degree (r=-0.67, r=0.69, respectively), and there was a significant correlation between FMD and IMT. In contrast, NTG-D did not correlate with CSI or IMT. Further, the diagnostic accuracy of FMD and IMT was comparable or even better than that obtained with conventional ST-segment depression during exercise in this cohort.

CONCLUSIONS

FMD in BA and IMT could represent a surrogate diagnostic method for assessment of CAD severity.

Effect of bare metal stenting on angiographic and clinical outcomes in diabetic and nondiabetic patients undergoing percutaneous coronary intervention of nonacute occluded coronary arteries: a report from the Total Occlusion Study of Canada (TOSCA)

The outcome after PTCA and coronary stenting of nonacute total coronary occlusions in the diabetic population is unknown. The main objective of the present report was to compare the angiographic and 1-year clinical outcomes in the diabetic and nondiabetic patients who were enrolled in the Total Occlusion Study of Canada (TOSCA), a prospective randomized controlled multicenter trial of primary stenting versus PTCA alone in nonacute native coronary artery occlusions. Of the 410 patients enrolled, 68 (16.5%) were diabetics. At 6-month follow-up, stenting resulted in significant improvement in angiographic outcome compared to PTCA alone in both diabetic and nondiabetic populations. Angiographic restenosis was significantly reduced by stenting in the nondiabetic population (69.3% vs. 55.2%; P = 0.009). A reduction in restenosis of a similar magnitude was observed with stenting in the diabetic population (71.1% vs. 59.3%; P = NS). At 1-year clinical follow-up, composite adverse cardiac event rates were similar for both strategies regardless of diabetic status. Target vessel revascularization was reduced by stenting compared to PTCA in diabetics (20% vs. 31.6%) and nondiabetics (21.5% vs. 30%). A significant reduction for any vessel revascularization following stenting compared to PTCA was observed in the nondiabetic population (28.5% vs. 38.8%; P = 0.05) but not in the diabetic subgroup (36.7% vs. 42%; P = NS). In conclusion, stenting appeared to be superior to PTCA alone, resulting in similar magnitude of reduction in angiographic restenosis and target vessel revascularization rates in diabetics and nondiabetics. Restenosis rates in all groups remain high. This analysis forms an important background for future studies that are needed to examine the effect of stenting with drug-eluting stents in diabetics as well as nondiabetics with nonacute coronary occlusions.

Cardiovascular disease morbidity and mortality in patients with type 1 diabetes mellitus : management strategies

There is an increased risk of cardiovascular disease (CVD) mortality and morbidity in patients with type 1 diabetes mellitus compared with the general population as shown by epidemiologic studies measuring cardiovascular endpoints, as well as by autopsy, angiographic, and coronary calcification studies. Most of the excess CVD risk associated with type 1 diabetes is concentrated in the subset of approximately 35% of patients who develop diabetic nephropathy (after 20 years of diabetes duration), who also typically have dyslipidemias, elevated blood pressure, and hyperglycemia, factors contributing to CVD. For reasons that remain speculative, the relative risks from CVD are higher in women than in men with type 1 diabetes compared with the general population, which effectively eliminates the gender differences in CVD. As in the general population and in patients with type 2 diabetes, education and lifestyle changes, interventions to reduce hyperglycemia, blood pressure, micro-albuminuria, lipid control, and the use of aspirin are important management areas in order to reduce the increased risk of CVD. Whether management with aspirin and statins should be started in type 1 diabetic patients at a younger age or at a lower risk score than in the general population is still under investigation. There is a need for a better understanding of the pathophysiology of vascular complications in type 1 diabetes, more specific risk engines in type 1 diabetes, and accurate estimations of the absolute and relative risk for CVD in order to improve management of CVD in these high-risk patients.

Coronary artery disease is common in nonuremic, asymptomatic type 1 diabetic islet transplant candidates

OBJECTIVE

Coronary artery disease (CAD) is the most common cause of death in patients with type 1 diabetes. Asymptomatic CAD is common in uremic diabetic patients, but its prevalence in nonuremic type 1 diabetic patients is unknown. The prevalence of CAD was determined by coronary angiography and the performance of noninvasive cardiac investigation evaluated in type 1 diabetic islet transplant (ITX) candidates with preserved renal function.

RESEARCH DESIGN AND METHODS

A total of 60 consecutive type 1 diabetic ITX candidates (average age 46 years [mean 24-64], 23 men, and 47% ever smokers) underwent coronary angiography, electrocardiographic stress testing (EST), and myocardial perfusion imaging (MPI) in a prospective cohort study. CAD was indicated on angiography by the presence of stenoses >50%. Models to predict CAD were examined by logistic regression.

RESULTS

Most subjects (53 of 60) had no history or symptoms of CAD; 23 (43%) of these asymptomatic subjects had stenoses >50%. CAD was associated with age, duration of diabetes, hypertension, and smoking. Although specific, EST and MPI were not sensitive as predictors of CAD on angiography (specificity 0.97 and 0.93, sensitivity 0.17 and 0.04, respectively) but helped identify two of three subjects requiring revascularization. EST and MPI did not enhance logistic regression models. A clinical algorithm to identify low-risk subjects who may not require angiography was highly sensitive but was applicable only to a minority (n = 8, sensitivity 1.0, specificity 0.27, negative predictive value 1.0).

CONCLUSIONS

Nonuremic type 1 diabetic patients with hypoglycemic unawareness and/or metabolic lability referred for ITX are at high risk for asymptomatic CAD despite negative noninvasive investigations. Aggressive management of cardiovascular risk factors and further investigation into optimal cardiac risk stratification in type 1 diabetes are warranted.

Mean HbA1c over 18 years predicts carotid intima media thickness in women with type 1 diabetes

AIMS/HYPOTHESIS

Intima media thickness (IMT) of the common carotid artery (CCA) is a validated surrogate marker of early atherosclerosis. The aim of our study was to assess the association between IMT in CCA and long-term mean HbA1c in type 1 diabetes. We also elucidated the association between carotid IMT and preclinical coronary atherosclerosis.

METHODS

In 39 individuals with type 1 diabetes, HbA1c was measured prospectively over 18 years. The IMT examinations were performed with high-resolution ultrasound. The association between carotid IMT and preclinical coronary atherosclerosis (assessed by intravascular ultrasound [IVUS]) was tested in 29 of the patients.

RESULTS

Mean HbA1c over 18 years was 8.2% (range: 6.6-11.3%). Mean age at follow-up after 18 years was 43 years and mean duration of diabetes was 30 years. IMT was significantly higher in diabetic patients than in an age- and sex-matched reference population. The IMT values were at the same level as for controls who were 20 years older. In women, HbA1c was significantly associated with mean average CCA IMT (r2=0.77, p<0.0001 when adjusted for age), whereas there was no significant association for men. Among women, a significant association was also found between carotid IMT and the percentage of coronary vessel area stenosis (r=0.65, p=0.03).

CONCLUSIONS/INTERPRETATION

The present findings suggest an important role of long-term hyperglycaemia in the development of atherosclerosis, especially in women with type 1 diabetes. Type 1 diabetes patients have earlier development of, and more advanced, atherosclerosis compared with an age- and sex-matched reference population. In women, carotid IMT reflects preclinical coronary atherosclerosis.

Considerable disturbances of cardiovascular risk factors in women with diabetes and myocardial infarction

OBJECTIVE

To investigate to which extent differences in cardiovascular risk factors explain the increased risk of myocardial infarction (MI) and complication rate in women with diabetes mellitus (DM).

DESIGN

Case-control study.

SUBJECTS

We compared women with diabetes and previous MI (n=29), diabetes but no MI (n=46), prior MI but no diabetes (n=64), and healthy controls (n=125).

MEASUREMENTS

Smoking habits, physical activity, blood pressure (BP), body mass index (BMI), waist/hip ratio (WHR), serum lipids, plasma fibrinogen, and serum sex hormones.

RESULTS

Despite the fact that diabetic women had similar BMI, those with a past MI, compared to diabetic women without MI, had significantly higher WHR (mean, 95% CI) [0.89 (0.87, 0.92) vs. 0.84 (0.81, 0.86) mmol/l, P=.001] and very high S-triglycerides [3.03 (2.23, 3.83) vs. 1.69, (1.39, 1.99) mmol/l, P=.001] and low HDL-cholesterol [1.09 (0.94, 1.24) vs. 1.56 (1.41, 1.71) mmol/l, P<.001], indicating pronounced metabolic disturbances. Women with MI but no diabetes had intermediate values for WHR, triglycerides, and HDL-cholesterol. Furthermore, women with diabetes and MI had significantly higher p-fibrinogen, were smokers, and lived a more sedentary life than the other women. Over half of all women with prior MI were on lipid-lowering therapy and tended to have nonsignificantly lower S-cholesterol than women without MI.

CONCLUSIONS

Women with diabetes who have manifested an MI carry a very substantial cardiovascular risk factor burden, which probably explain their increased morbidity and mortality. In order to improve prognosis, studies targeted at investigating treatment modalities for these abnormalities are needed.

Lifetime glycaemic exposure predicts reduced coronary vasoreactivity in Type 1 diabetic subjects

AIMS

Subjects with Type 1 diabetes have impaired coronary vasoreactivity but the independent role of glycaemic control on myocardial perfusion is less clear. We examined the effect of lifetime glycaemic exposure on coronary vasoreactivity in 43 otherwise healthy Type 1 diabetic subjects.

METHODS

Myocardial blood flow was calculated basally and during pharmacologically induced hyperaemia in the fasting state and during euglycaemic hyperinsulinaemic clamp (at an insulin infusion rate of 1 mU/kg per min for 60 min) using positron emission tomography and (15)O-water. Glycaemic exposure was estimated as glycosylated haemoglobin A(1c) (HbA(1c)) months.

RESULTS

Hyperaemic myocardial blood flow was inversely associated with log HbA(1c) months in the fasting state (r = -0.72, P < 0.01) and during clamp (r = -0.35, P < 0.05). These correlations remained significant after adjustment for lipid values, blood pressures, sex, smoking, body mass index (BMI) and age (r = -0.70, P < 0.05 and r = -0.35, P < 0.05, respectively). No significant correlation was detected between hyperaemic flow and HbA(1c) or plasma glucose values measured immediately preceding the PET study.

CONCLUSIONS

The present study demonstrates that the lifetime glycaemic exposure appears to be a better predictor of reduced coronary vasoreactivity than recent glycaemic control in Type 1 diabetic subjects. Reduced coronary vasoreactivity in diabetic subjects with poor glycaemic control and/or long duration of diabetes may represent an early precursor of coronary artery disease.

Long-term prognosis of patients having acute myocardial infarction when </=40 years of age

Data on the long-term prognosis of acute myocardial infarction (AMI) in young patients are limited. This study investigated long-term survival and risk predictors in a series of 108 consecutive patients </=40 years old who represented 4% of 2,644 patients who presented with AMI at a single center between June 1986 and April 1992. Four patients died soon after admission. The overall mortality rate of the 104 survivors was 25.5% at 15 years. The mortality rate was higher in patients who had type 1 diabetes mellitus (p = 0.01), long-term excessive alcohol intake (p = 0.035), peripheral arterial disease (p = 0.004), previous AMI (p = 0.04), anterior AMI (p = 0.01), and depressed left ventricular ejection fraction (p <0.0001). Cumulative survival rates (Kaplan-Meier analysis) at 1, 5, 10, and 15 years were 99%, 95%, 86%, and 75%, respectively. Event-free survival rates (death, AMI, coronary intervention, severe angina pectoris, malignant arrhythmias, and congestive heart failure) at the same times were 88%, 76%, 60%, and 43%, respectively. The strongest independent predictors of the long-term mortality rate were ejection fraction </=45% (odds ratio 4.4, 95% confidence interval 1.6 to 12.4, p <0.001) and peripheral arterial disease (odds ratio 45.9, 95% confidence interval 3.79 to 555, p <0.0001). These data suggest that the long-term prognosis and functional status of young patients who have AMI are not benign, especially when ejection fraction is decreased or peripheral atherosclerotic disease is present.

Anatomy of coronary disease in diabetic patients: an explanation for poorer outcomes after percutaneous coronary intervention and potential target for intervention

There are over 1.3 million known diabetic patients in the UK and a similar number who have the disease undiagnosed. Over 90% have non-insulin dependent diabetes mellitus usually characterised by insulin resistance and adult onset. Over half of all diabetic patients die of coronary disease and account for over a fifth of percutaneous coronary intervention (PCI) revascularisation procedures. Despite recent therapeutic advances such as new antiplatelet treatments and drug eluting stents, outcomes for diabetic patients after PCI are still significantly worse than for non-diabetic patients. This article summarises what is known about the pattern and severity of diabetic coronary disease, what mechanisms are responsible for these differences, and whether this information can help explain the poorer prognosis for these patients after PCI and form the basis of interventions to improve outcome.

Long-term follow-up of coronary artery disease presenting in young adults

OBJECTIVES

This study evaluated long-term survival and predictors of elevated risk for young adults diagnosed with coronary artery disease (CAD).

BACKGROUND

Coronary artery disease is rarely seen in young adults. Traditional cardiac risk factors have been studied in small series; however, many questions exist.

METHODS

We identified 843 patients under age 40 with CAD diagnosed by coronary angiography from 1975 to 1985. Death, hypertension, gender, family history, prior myocardial infarction (MI), diabetes, heart failure, angina class, number of diseased vessels, ejection fraction (EF), Q-wave infarction, in-hospital death, and initial therapy were studied. Patients were followed for 15 years.

RESULTS

The mean age was 35 for women (n = 94) and 36 for men (n = 729). The average EF was 55%. Fifty-eight percent of the subjects had single-vessel disease, and 10% were diabetic. The strongest predictors of long-term mortality were a prior MI (hazard ratio [HR] 1.32, 95% confidence interval [CI] 1.00 to 1.73), New York Heart Association class II heart failure (HR 1.75, 95% CI 1.03 to 2.97), and active tobacco use (HR 1.59, 95% CI 1.14 to 2.21). Revascularization, rather than medical therapy, was associated with lower mortality (coronary angioplasty: HR 0.51, 95% CI 0.32 to 0.81; coronary artery bypass graft: HR 0.68, 95% CI 0.50 to 0.94). Overall mortality was 30% at 15 years. Patients with diabetes had 15-year mortality of 65%. Those with prior MI had 15-year mortality of 45%, and patients with an EF <30% a mortality of 83% at 15 years.

CONCLUSIONS

Coronary disease in young adults can carry a poor long-term prognosis. A prior MI, diabetes, active tobacco abuse, and lower EF predict a significantly higher mortality.

Screening for treatable left ventricular abnormalities in diabetic patients

Cardiovascular disease is the leading cause of death in patients with diabetes mellitus. Attempts to improve this statistic tend to focus primarily on the prevention of coronary artery disease. However, coronary artery disease is not the sole cause of cardiac death in diabetic patients; left ventricular dysfunction (LVD) and left ventricular hypertrophy (LVH) are also implicated and, unlike coronary artery disease, are ideal targets for screening. The treatment of left ventricular abnormalities, even when these are asymptomatic, is associated with prognostic benefit. Prescreening diabetic patients with plasma B-type natriuretic peptide (BNP) may permit identification of those who are likely to have left ventricular abnormalities, so that they may be put forward for echocardiography and receive targeted therapy.