Enzymatic evidence of impaired reperfusion in diabetic patients after thrombolytic therapy for acute myocardial infarction: a role for plasminogen activator inhibitor?

Plasminogen activator inhibitor 1 in acute coronary syndromes

Plasminogen activator inhibitor 1 (PAI-1) is the main regulator of endogenous fibrinolysis, overriding the impact of other constituents of fibrinolysis. In plasma, it can be found in three forms: active, latent and inactive. There are numerous commercially available tests, analysing the activity of PAI-1 or the antigen level, with variable correlations between the two. PAI-1 has been extensively studied regarding incidence and outcomes of acute coronary syndromes, and showed positive association with both in numerous studies. Higher PAI-1 has been associated with worse short- and long-term outcomes. Studies are more consistent in the primary percutaneous coronary intervention era. Higher rise of PAI-1 within the first 24 h of acute myocardial infarction has been linked to some of its high-risk features. The circadian pattern of PAI-1 kinetics has been previously described, and the mechanisms behind this phenomenon and its impact on the incidence of acute coronary syndromes are well known. Further investigations are needed to test the safety and efficacy of PAI-1 as a pharmacological target in cardiovascular diseases.

Association between plasminogen activator inhibitor-1 and cardiovascular events: a systematic review and meta-analysis

Background

Small studies have implicated plasminogen activator inhibitor-1 (PAI-1) as a predictor of cardiovascular events; however, these findings have been inconsistent.

We sought out to examine the potential role of PAI-1 as a marker for major adverse cardiovascular events (MACE).

Methods

We systematically reviewed all indexed studies examining the association between PAI-1 and MACE (defined as death, myocardial infarction, or cerebrovascular accident) or restenosis. EMBASE, Web of Science, Medline, and the Cochrane Library were searched through October 2016 to identify relevant studies, supplemented by letters to authors and review of citations. Studies reporting the results of PAI-1 antigen and/or activity levels in association with MACE in human subjects were included.

Results

Of 5961 articles screened, we identified 38 articles published between 1991 to 2016 that reported PAI-1 levels in 11,557 patients. In studies that examined PAI-1 antigen and activity levels, 15.1% and 29.6% of patients experienced MACE, respectively. Patients with MACE had higher PAI-1 antigen levels with a mean difference of 6.11 ng/mL (95% CI, 3.27-8.96). This finding was similar among patients with and without known coronary artery disease. Comparatively, studies that stratified by PAI-1 activity levels were not associated with MACE. In contrast, studies of coronary restenosis suggest PAI-1 antigen and activity levels are negatively associated with MACE.

Conclusions

Elevated plasma PAI-1 antigen levels are associated with MACE. Definitive studies are needed to ascertain if PAI-1 acts simply as a marker of risk or if it is indeed a bona fide therapeutic target.

Electronic supplementary material

The online version of this article (10.1186/s12959-018-0166-4) contains supplementary material, which is available to authorized users.

PPAR-γ receptor agonists-a review of their role in diabetic management in Trinidad and Tobago

The PPAR-γ receptor agonists, as a relatively new and perhaps still not very widely used class of antidiabetic agent in the Caribbean and particularly the Trinidadian context, possess pharmacologic properties that certainly have been shown to have impact on many of the inflammatory, metabolic, biochemical and structural macrovascular aberrations that occur in the type 2 diabetic. Activation of PPAR(gamma) nuclear receptors regulates the transcription of insulin-responsive genes involved in the control of glucose production, transport, and utilization. PPAR(gamma)-responsive genes also participate in the regulation of fatty acid metabolism, an important contributory pathogenic factor in this subset of patients. The unique mode of action of this class of therapeutic agent addresses a range of anomalies occurring at the cellular and sub-cellular level that are injurious to the diabetic. My aim in addressing the issue of the potential impact of PPAR-γ receptor agonists on cardiovascular disease (CVD) morbidity and mortality in the diabetic, is first, to seek to enhance both an awareness of, and greater familiarity among our own physicians, with this class of drug, and secondly, to effect a timely review of the recent literature as it relates to the tremendous possibilities for the potential clinical gains that might accrue from their use, in so far as this may serve to ameliorate the ravages of the CVD disease that all too tragically attends the type 2 diabetic, and more specifically those with the insulin resistance syndrome. (Mol Cell Biochem 263: 189-210, 2004).

Assessment of coronary heart diseases in diabetics in al-Madinah al-Munawarah

BACKGROUND

Coronary heart disease is highly prevalent and a major cause of morbidity and mortality in diabetic patients. The aim of this study was to assess the major risk factors and their predictor score for coronary heart diseases in diabetic patients.

METHODS

The present study was conducted in al-Madinah, Kingdom of Saudi Arabia. Using a cross-sectional case control study, 262 outpatient diabetics and 264 matched control subjects were examined for the risk factors and risk predictor scores for ischemic heart disease. The mean age of the patient and control groups was 49.61 ± 12.93 years and 48.39 ± 11.60 years, respectively.

RESULTS

Diabetic patients had significantly higher positive family history of diabetes, but no significant difference regarding their family history of hypertension. There was a significantly higher body mass index (33.67 kg/m(2)), glycosylated hemoglobin (7.26%), significantly higher cholesterol, low-density lipoprotein, and triglyceride in diabetics compared to control. Diabetic patients had higher risk for developing coronary heart disease with a mean risk score of 6.07 while the control subject risk score was -6.81. However, females showed significantly higher risk for coronary heart diseases than did males.

CONCLUSION

Our study replicates the known fact of higher risk in diabetes, but higher risk of coronary heart disease in female diabetics compared with male diabetics.

Prognostic role of plasminogen-activator-inhibitor-1 levels in treatment with streptokinase of patients with acute myocardial infarction

BACKGROUND

The antifibrinolytic effect of plasminogen-activator-inhibitor type 1 (PAI-1) may be responsible for delays in reperfusion and/or reinfarctions after streptokinase (STK) therapy in patients with acute myocardial infarction (AMI).

HYPOTHESIS

This study aimed to demonstrate the prognostic role of pretreatment PAI-1 levels for the outcome of STK therapy in patients with AMI, depending on reperfusion and/ or reinfarction.

METHODS

The mean pretreatment PAI-1 level of 104 patients with AMI, treated with STK, determined by chromogenic method, was 5.8 +/- 8.6 U/ml, range 0.3-66.2 U/ml. Streptokinase therapy was successful when reperfusion was achieved, as assessed noninvasively, without subsequent reinfarction; it failed when reperfusion was delayed and/or reinfarction developed.

RESULTS

Fibrinolysis with STK failed significantly in patients with elevated pretreatment PAI-1 levels (p < 0.05), especially with levels >4.0 U/ml (p< 0.01). The mean pretreatment PAI-1 level was significantly higher in unsuccessfully treated patients. Multivariate statistical testing demonstrated that among pretreatment variables, elevated PAI-1 activity was the most significant independent risk factor of failed fibrinolysis with STK.

CONCLUSIONS

Among pretreatment variables, elevated pretreatment PAI-1 activity in patients with AMI was the most significant independent risk factor of failed fibrinolysis with STK, especially at levels > 4.0 U/ml.

The impact of the PAI-1 4G/5G polymorphism on the outcome of patients with ALI/ARDS

INTRODUCTION

Increased levels of plasminogen activator inhibitor-1 (PAI-1) have been associated with worse outcome in ALI/ARDS. A single guanosine insertion/deletion (4G/5G) polymorphism in the promoter region of the PAI-1 gene, may play an important role in the regulation of PAI-1 expression. The objective of the study was to evaluate the effect of this polymorphism on the outcome of critically ill patients with ALI/ARDS.

MATERIALS AND METHODS

52 consecutive ventilated patients with ALI/ARDS were studied. Bronchoalveolar lavage was performed within 48 hours from diagnosis. Measurement of plasma and BALF PAI-1 activity and D-dimers levels, and 4G/5G genotyping of PAI-1 were carried out. The primary outcome was 28-day mortality, and secondary outcomes included organ dysfunction and ventilator-free days.

RESULTS

17 patients were homozygotes for the 4G allele. Severity scores were not different between subgroups upon study enrollment. 28-day mortality was 70.6% and 42.9% for the 4G-4G and the non-4G-4G patients, respectively (p=0.06). PAI-1 activity levels and D-dimer in plasma and BALF were not significantly different between the 4G-4G and the non-4G-4G subgroups. In the multivariate analysis, genotype 4G/4G was the only variable independently associated with 28-day mortality (Odds Ratio=9.95, 95% CI: 1.79-55.28, p=0.009). Furthermore, genotype 4G/4G and plasma PAI-1 activity levels were independently negatively associated with ventilator free days (p=0.033 and p=0.008, respectively).

CONCLUSIONS

ALI/ARDS patients, homozygous for the 4G allele of the PAI-1 gene, experienced higher 28-day mortality. This genotype was associated with a reduction in the number of days of unassisted ventilation and was inversely associated with the number of days without organ failure.

The influence of acute-phase levels of haemostatic factors on reperfusion and mortality in patients with acute myocardial infarction treated with streptokinase

BACKGROUND

The fibrinolytic system and von Willebrand factor (vWF) have been shown to play a role as risk factors for myocardial infarction. We performed this prospective cohort study to determine if components in the fibrinolytic system or vWF before or during treatment of AMI with streptokinase (SK) could predict reperfusion, recurrent ischaemia, reinfarction or mortality at one year, or mortality at five years. Reperfusion and recurrent ischaemia were assessed by continuous vectorcardiography. The setting was Umeå university hospital and Skellefteå county hospital, Sweden.

RESULTS

139 patients were included; successful reperfusion was obtained in 53%. tPA activity, PAI-activity, PAI-mass concentration and vWF were analysed immediately on arrival and after 4 and 10 h. High fibrinolytic activity, measured as tPA activity > 25 U/L after the start of treatment, was associated with reperfusion. No significant associations between pre-treatment levels of the fibrinolytic variables or vWF and reperfusion or recurrent ischaemia were found. Elevated levels of PAI-1 mass concentration and PAI-1 activity after the start of SK treatment were associated with a higher risk for death at one year, but not at five years. High levels of vWF were associated with worse prognosis but not when corrected for age.

CONCLUSION

Pre-treatment levels of PAI-1, vWF and tPA activity showed no association with reperfusion or recurrent ischaemia. Elevated levels of PAI-1 activity after the start of treatment were associated with worse prognosis.

Clinical and biochemical predictors affect the choice and the short-term outcomes of different thrombolytic agents in acute myocardial infarction

BACKGROUND

The presence of plasminogen activator inhibitor-1, angiotensin-converting enzyme and others may play a role in unsuccessful recanalization after thrombolytic therapy.

OBJECTIVES

To find out the clinical and biochemical predictors that may affect the choice and short-term outcomes following different thrombolytic agents in acute myocardial infarction.

METHODOLOGY

Angiotensin-converting enzyme and plasminogen activator inhibitor-1 plasma levels of 184 patients with acute myocardial infarction, treated with streptokinase, metalyze or reteplase, were determined. Failure of thrombolysis was assessed by noninvasive reperfusion criteria. Prolonged hospitalization, impaired left ventricular ejection fraction and reinfarction were considered as short-term outcomes.

RESULTS

Patients who received streptokinase developed higher incidence of >50% resolution of ST-segment elevation (82.5 vs. 64.7%, P-value<0.05, in comparison with metalyze and 82.5 vs. 55.7%, P-value 0.001, in comparison with reteplase) than those who received other thrombolytic agents. High plasma angiotensin-converting enzyme was associated with prolonged hospitalization (55, 63 and 94%, P<0.02) following streptokinase, metalyze and reteplase, respectively. High plasma plasminogen activator inhibitor-1 is associated with impaired left ventricular ejection fraction (55.3, 76.7 and 68.5%, P<0.09), ST resolution<50% (13.2, 36.7 and 37.5%, P=0.03), ST resolution>50% (86.8, 63.3 and 62.5%, P=0.03) following streptokinase, metalyze and reteplase, respectively.

CONCLUSIONS

Rapid determination of pretreatment angiotensin-converting enzyme and plasminogen activator inhibitor-1 plasma levels in patients with acute myocardial infarction may influence the choice and outcomes of the thrombolytic agents. The presence of a high plasma level of either angiotensin-converting enzyme or plasminogen activator inhibitor-1 is significantly associated with adverse short-term outcomes after treatment with reteplase or metalyze.

Increase in plasma plasminogen activators inhibitor type 1 concentration after fibrinolytic treatment in patients with acute myocardial infarction is associated with 4G/5G polymorphism of PAI-1 gene

BACKGROUND

Preliminary data suggest that plasma concentration of plasminogen activators inhibitor type 1 (PAI-1) is genetically determined and may be related to differential regulation of plasma PAI-1 concentration at baseline and after stimulation.

AIM

This study aimed to evaluate whether increase in the plasma PAI-1 antigen concentration or activity after fibrinolytic therapy in patients with acute myocardial infarction is associated with the -675 4G/5G genetic polymorphism in the promoter region of PAI-1 gene.

RESULTS & CONCLUSIONS

Our study revealed that a rebound effect is observed in PAI-1 activity (ActPAI-1) and PAI-1 antigen (AgPAI-1) concentration after standard streptokinase treatment with maximal values of 3 h (t3) after the completion of streptokinase infusion. Both ActPAI-1 and AgPAI-1 were significantly higher at t3 compared to the levels before fibrinolytic treatment: 37.3 (20.0-67.7) vs. 10.0 (3.6-26.0) IU L(-1); P = 0.00001 and 29.9 (15.6-42.3) vs. 20.9 (13.0-30.2) ng mL(-1); P = 0.001, respectively. The stratification of the patients by genotype revealed that carriers of the 4G allele had higher concentrations of PAI-1 antigen 3 h after streptokinase infusion: 30.9 vs. 13.8 ng mL(-1); P = 0.019. No significant association between PAI-1 activity and genotype was found. In conclusion, the rebound effect in serum PAI-1 concentration observed after streptokinase treatment may be related to the 4G/5G polymorphism in the PAI-1 gene promoter.

The effect of high plasma levels of angiotensin-converting enzyme (ACE) and plasminogen activator inhibitor (PAI-1) on the reperfusion after thrombolytic therapy in patients presented with acute myocardial infarction

The resistance to thrombolytic agents and delays in reperfusion occur in more than 30% after acute myocardial infarction. This may play an important role in the unsuccessful recanalization after thrombolytic therapy. The aim of this study is to assess the clinical and biochemical markers of reperfusion after different types of thrombolytic therapy and to find out the relationship between PAI-1 and ACE serum levels and the short-term outcome. Pretreatment ACE and PAI-1 plasma levels of 184 patients with acute myocardial infarction, treated with thrombolytic therapy were determined. Failure of thrombolysis was considered when reperfusion was delayed as assessed by noninvasive reperfusion criteria, reinfarction, and impaired left ventricular function. High plasma level of ACE (> 50 U/L), PAI-1 (> 43 ng/ml) and both was found in 57, 108 and 32 patients respectively. Subjects with high ACE plasma levels were characterized by impaired LV systolic function (79.0% vs. 75.0%), new Q-wave (88.4% vs. 74.2%), less reperfusion arrhythmia (19.3% vs. 22.8%) and prolonged hospitalization (70% vs. 66%) but no statistical significance was observed. High enzymes levels of PAI-1 were observed with higher incidence of anterior myocardial infarction (50.0% vs. 41.0%), lesser ST segment resolution (65.6% vs. 58.8%), reinfarction (6.3% vs. 5.9%), and impaired LV systolic function (90.6% vs. 76.0%), and prolonged hospitalization (70.4% vs. 63.4). There was a statistically significant difference between thrombolytic agents in the presence of high ACE regarding hospital overstay (p = 0.02). While the presence of high PAI-1 was significantly affect the degree of ST-segment resolution (p = 0.03).

CONCLUSION

High plasma ACE and/or PAI-1 plays a considerable role in the higher incidence of unsuccessful reperfusion and impaired left ventricular function after thrombolytic therapy. A rapid diagnostic tool that enables physician of detecting those enzymes before giving thrombolytic therapy may change the strategy of treatment to offer another effective revascularization method.

Treatment modalities of diabetes mellitus and outcomes of acute coronary syndromes

BACKGROUND

Oral treatments for diabetes mellitus (DM) may have a deleterious effect on acute coronary syndromes (ACS) outcomes.

AIM

We aimed to examine in-hospital mortality among patients with ACS and DM and the impact of anti-DM treatment modalities.

METHODS AND RESULTS

The Euro Heart Survey ACS prospectively enrolled 10484 patients across Europe and the Mediterranean basin. Of the 10214 patients with recorded DM status, 2352 (23.0%) had DM, of whom 562 were on diet alone, 1112 received oral hypoglycaemics, 561 received insulin, and 117 received both. The in-hospital mortality for ST-elevation-ACS was 9.8 and 5.7% for patients with and without DM, respectively, with an adjusted risk (95% confidence interval) of in-hospital mortality of 1.6 (1.2, 2.1). The in-hospital mortality for non-ST-elevation-ACS was 2.8 and 2.0%, accordingly, with an adjusted risk (95% confidence interval) of in-hospital mortality of 1.2 (0.8, 1.9). The in-hospital mortality for undetermined-electrocardiographic-pattern-ACS was 11.5 and 10.9%, accordingly, with an adjusted risk of in-hospital mortality of 1.1 (0.6, 2.0). Among DM patients with ST-elevation-ACS, the adjusted risks of in-hospital mortality were 1.0 for diet therapy, 0.8 (0.4, 1.5) for oral hypoglycaemics, and 1.9 (1.0, 3.8) for insulin; for DM patients and non-ST-elevation-ACS, 1.0 for diet therapy, 2.2 (0.6, 7.8) for oral hypoglycaemics, and 3.5 (1.0, 12.5) for insulin; for DM patients and undetermined-electrocardiographic-pattern-ACS, the adjusted risks of in-hospital mortality were 1.0 for diet therapy, 0.9 (0.2, 4.6) for oral hypoglycaemics, and 2.1 (0.5, 9.5) for insulin.

CONCLUSIONS

Acute coronary syndrome patients with DM, especially those with ST-elevation, had increased in-hospital mortality. Among ACS patients with DM, those receiving insulin had worse outcomes. Outcomes were similar for those on hypoglycaemics or on diet alone.

Diabetes mellitus adversely affects the outcomes of thrombolytic therapy in patients with acute myocardial infarction

This study was performed to evaluate whether coexistent diabetes mellitus has any adverse effect on the outcomes of thrombolytic therapy in patients with acute myocardial infarction. Although the early reperfusion rates were similar between the two groups of patients who had acute myocardial infarction with and without diabetes mellitus (42% vs 45.4%, p > 0.05), the results of late angiographic examination showed a significantly lower rate of patency in infarct-related coronary artery (defined as TIMI 3 flow) in diabetics compared to nondiabetics (28.9% vs 41.3%, p < 0.001). The global left ventricular function was also poorer in diabetics (left ventricular wall motion score was 18.6 +/- 7.3 in diabetics and 14.1 +/- 4.6 in nondiabetics, p < 0.01).

Evaluation and management of metabolic and coagulative disorders in HIV-infected patients receiving highly active antiretroviral therapy

A number of metabolic disorders, including hypercholesterolemia, hypertriglyceridemia, insulin resistance, elevated fasting glucose and diabetes mellitus, were reported in a high proportion of HIV-infected patients receiving highly active antiretroviral therapy (HAART). Less frequently, coagulative disorders were described in patients receiving HAART. Since all these metabolic disorders may predispose to coronary heart disease, an early evaluation and treatment is advisable. Existing guidelines for uninfected patients may be applied, taking into account, however, the potential for drug interactions and accumulated toxicity. It may be helpful to stratify all patients in three risk groups to plan regular diagnostic screening. Treatment of dyslipidemia and diabetes mellitus should include a first-line approach with non-pharmacological interventions. Statins and fibrates are proposed for HIV-infected patients with HAART-related hyperlipidemia, but concern has been raised on their potential for interaction with antiretrovirals and hepatic and muscle toxicity. Metformin and thiazolidenediones (or glitazones), hypoglycemic agents that increase insulin sensitivity, are presently under evaluation in diabetic and glucose-intolerant HIV-infected patients treated with HAART. Glitazones also have a potential for ameliorating the lipodystrophic syndrome. The routine evaluation of coagulative parameters is probably not advisable until a benefit of widespread screening is assessed in prospective studies. A heightened awareness of the possiblity of coagulative disorders, together with controlled trials and basic research, is needed.

Angiographic findings, time course of regional and global left ventricular function, and clinical outcome in diabetic patients with acute myocardial infarction treated with primary percutaneous transluminal coronary angioplasty

There is scarce information available about the outcome of diabetic patients with acute myocardial infarction (AMI) treated with percutaneous transluminal coronary angioplasty (PTCA). We sought to compare left ventricular (LV) function, and angiographic and clinical outcomes in diabetics versus nondiabetics with AMI treated with primary PTCA. This study examined 720 consecutive patients with AMI treated with primary PTCA, 102 of whom had diabetes. Six-month follow-up coronary angiography was obtained in 560 patients (88% of eligible patients). In a subgroup of 284 patients, LV function was serially determined by 2-dimensional echocardiography. During 6-month follow-up no significant differences were observed between diabetics and nondiabetics with regard to restenosis rates (31.6% vs 28.2%, p = 0.6), recovery of LV function (6-month wall motion score index: 1.8 +/- 0.7 vs 1.8 +/- 0.7, p = 0.88; 6-month LV ejection fraction: 48.5 +/- 12% vs 51.2 +/- 13%, p = 0.173), nonfatal re-AMI rates (2.9% vs 1.3%, p = 0.2), and target vessel revascularization rates (21.6% vs 16.8%, p = 0.2). Early and late mortality were higher in diabetics than in nondiabetic patients (8.8% vs 4.2%, p = 0.045 and 11.7% vs 5.5%, p = 0.016, respectively). By Cox analysis, diabetes was an independent predictor of both early (odds ratio [OR] 2.4, 95% confidence interval [CI] 1.1 to 5.3, p = 0.03) and late mortality (OR 2.37, 95% CI 1.16 to 4.84, p = 0.017) as well as 6-month major adverse cardiac events (MACEs): death, re-AMI, target vessel revascularization (OR 1.51, 95% CI 1.04 to 2.18, p = 0.03). Thus, diabetes is an independent predictor of clinical outcome even if PTCA is used as the primary reperfusion strategy.

Hereditary and acquired defects in the fibrinolytic system associated with thrombosis

The fibrinolytic system plays a pivotal role in the regulation of hemostasis and the prevention of thrombosis. There are no drugs that will increase the plasma fibrinolytic activity for a lasting duration to prevent thrombotic events effectively. Despite the ability of vasoactive agents such as nicotinic acid and metformin to release PA from the vessel wall, this therapeutic effect has not been evaluated adequately. The PAs are short-acting and indicated only for thrombolysis and not for prophylaxis. Future directions are directed at finding, agents that can enhance plasminogen activator release or inhibit PAW-1 activity. As there are multiple factors involved in the pathogenesis of thrombosis, there are a number of conditions in which abnormal fibrinolysis is only a contributory factor. Examples are seen in pregnancy, especially during puerperium, when the thromboembolic risk is at its highest. The levels of inhibitors of fibrinolysis. both PAI-1 and PAI-2, are also at their highest. Another example was seen recently in the antiphospholipid syndrome, where antibodies against Annexin II, a receptor for tPA, were found to be higher than in healthy controls. Thus, a thorough investigation into other hereditary and acquired risk factors for thrombosis is recommended.

Plasminogen activator inhibitor-1 in patients with atrial arrhythmias during acute myocardial infarction, treated with streptokinase

Atrial arrhythmias (AA), especially atrial fibrillation (AF), during acute myocardial infarction (AMI) are often associated with increased mortality and heart failure. Impaired fibrinolysis with elevated plasminogen activator inhibitor-1 (PAI-1) activity is associated with resistance to fibrinolytic therapy in AMI patients, but it is also found in patients with AF. Our aim was a prospective study of the role of pre-treatment PAI-1 levels for the presence of AA in AMI patients and the influence of AA on in-hospital mortality. In 116 AMI patients, treated with streptokinase, pre-treatment PAI-1 levels were estimated by the chromogenic method (normal levels, 0.3-3.5 U/ml) and in-hospital AA were assessed as atrial fibrillation, flutter and/or tachycardias. Between patients with and without AA, a significant difference was observed in mean pre-treatment PAI-1 levels, in several in-hospital complications and mortality (24 versus 4.4%; P < 0.01; odds ratio, 6.45; 95% confidence interval, 1.66-25.0). The PAI-1 level > 7 U/ml was the most significant independent pre-treatment risk factor for AA (P < 0.05; odds ratio, 3.5; 95% confidence interval, 1.15-10.6). We conclude that AA were a significant risk for in-hospital mortality of AMI patients, treated with streptokinase. A pre-treatment PAI-1 level > 7 U/ml was the most significant pre-treatment risk for AA in these patients.

Clinical outcomes of patients with diabetes mellitus and acute myocardial infarction treated with primary angioplasty or fibrinolysis

OBJECTIVE

To compare the early and late outcomes of primary percutaneous transluminal coronary angioplasty (PTCA) with fibrinolytic treatment among diabetic patients with acute myocardial infarction (AMI).

DESIGN

Retrospective observational study with data obtained from prospective registries.

SETTING

Tertiary cardiovascular institution with 24 hour acute interventional facilities.

PATIENTS

202 consecutive diabetic patients with AMI receiving reperfusion treatment within six hours of symptom onset.

INTERVENTIONS

Fibrinolytic treatment was administered to 99 patients, and 103 patients underwent primary PTCA. Most patients undergoing PTCA received adjunctive stenting (94.2%) and glycoprotein IIb/IIIa inhibition (63.1%).

MAIN OUTCOME MEASURES

Death, non-fatal reinfarction, and target vessel revascularisation at 30 days and one year were assessed.

RESULTS

Baseline characteristics were similar in these two treatment groups except that the proportion of patients with Killip class III or IV was considerably higher in those treated with PTCA (15.5% v 6.1%, p = 0.03) and time to treatment was significantly longer (103.7 v 68.0 minutes, p < 0.001). Among those treated with PTCA, the rates for in-hospital recurrent ischaemia (5.8% v 17.2%, p = 0.011) and target vessel revascularisation at one year (19.4% v 36.4%, p = 0.007) were lower. Death or reinfarction at one year was also reduced among those treated with PTCA (17.5% v 31.3%, p = 0.02), with an adjusted relative risk of 0.29 (95% confidence interval 0.15 to 0.57) compared with fibrinolysis.

CONCLUSION

Among diabetic patients with AMI, primary PTCA was associated with reduced early and late adverse events compared with fibrinolytic treatment.

Plasminogen activator inhibitor type-1 in cardiovascular disease. Status report 2001

Plasminogen activator inhibitor type-1 (PAI-1) is known to contribute to thrombus formation and to the development and the clinical course of acute and chronic cardiovascular disease, as well as of other arterial and venous thromboembolic diseases. Recently, an important role of elevated pretreatment levels of PAI-1 for failure of thrombolytic therapy of acute myocardial infarction has been discussed. PAI-1 plasma levels depend on the one hand on gene regulation but are related on the other hand to known risk factors of atherosclerosis like insulin resistance, diabetes or hypertriglyceridemia, respectively. Furthermore, an activated renin-angiotensin-aldosterone system (RAAS) significantly contributes to the upregulation of PAI-1 concentration via a receptor-mediated mechanism. In accordance to the known mechanisms of regulation of PAI-1 plasma levels, the use of specific agents like antidiabetic drugs, fibrates, statins, ACE inhibitors and angiotensin II type-1 receptor-blockers may contribute to the downregulation of circulating PAI-1 and, therefore, increase the fibrinolytic capacity and consecutively counteract the thrombotic tendency. To further improve the efficacy of thrombolytic therapy, a PAI-1 resistant variant of t-PA, TNK-t-PA, has been developed and is now available for acute myocardial infarction.

Stress echocardiography for risk stratification of diabetic patients with known or suspected coronary artery disease

OBJECTIVE

Coronary artery disease (CAD) is a leading cause of mortality and morbidity in diabetic patients; therefore, their risk stratification is a relevant issue. Because exercise tolerance is frequently impaired in these patients, pharmacological stress echocardiography (SE) has been suggested as a valuable alternative. Our aim was to evaluate the prognostic value of this technique in diabetic patients with known or suspected CAD.

RESEARCH DESIGN AND METHODS

A total of 259 consecutive diabetic patients underwent pharmacological SE (dobutamine in 108 patients and dipyridamole in 151 patients) and follow-up for 24 +/- 22 months. A comparison between the prognostic value of SE and exercise electrocardiography (ECG) was made in a subgroup of 120 subjects.

RESULTS

A total of 13 cardiac deaths and 13 nonfatal infarctions occurred during follow-up, and 58 patients were revascularized. Univariate predictors of outcome were known CAD, positive SE, rest and peak wall motion score index (WMSI), and peak/rest WMSI variation. Peak WMSI was the only significant and independent prognostic indicator (odds ratio 11; 95% CI 4-29, P < 0.0001) on multivariate Cox's analysis. After adjustment for the most predictive clinical and exercise ECG variables, SE provided 43% additional prognostic information (gain in X(2) = 7, P < 0.01). Moreover, positive SE was associated with a significantly lower event-free survival.

CONCLUSIONS

SE effectively predicts cardiac events in diabetic patients with known or suspected CAD and adds additional prognostic information as compared with exercise ECG.

Plasminogen activator inhibitor type-1 (part two): role for failure of thrombolytic therapy. PAI-1 resistance as a potential benefit for new fibrinolytic agents

Rapid and sustained reperfusion of an occluded coronary artery is the goal of thrombolytic therapy in acute myocardial infarction. However, the clot-dissolving efficacy of fibrinolytic agents such as tissue-type plasminogen activator (t-PA) is limited, in vivo, in part by the action of plasminogen activator inhibitor type-1 (PAI-1). A new generation of fibrinolytic agents has been genetically engineered to have greater resistance to PAI-1 inhibition. This article reviews the pathophysiologic role of PAI-1 in failure of thrombolytic therapy and describes the advantages that PAI-1-resistance may confer upon fibrinolytic agents such as TNK-t-PA, the new fibrinolytic agent with the most powerful PAI-1 resistance.

Effect of diabetes mellitus and insulin use on survival after acute myocardial infarction in the elderly (the Cooperative Cardiovascular Project)

Using data from a retrospective cohort study of Medicare beneficiaries hospitalized with an acute myocardial infarction (AMI), we evaluated the role of diabetes mellitus on 30-day and 1-year mortality. We classified subjects as nondiabetics, diabetics controlled with diet alone, diabetics receiving an oral hypoglycemic agent, and diabetics on insulin at time of admission. We compared baseline admission characteristics of subgroups using chi-square and Wilcoxon rank-sum tests and evaluated the effect of each diabetic state using sequential logistic models. We identified 80,832 nondiabetic patients, 9,862 diet-controlled diabetic patients, 14,664 diabetics receiving an oral hypoglycemic agent, and 12,241 diabetic patients on insulin therapy. Although mean age was similar among the groups, prevalence of hypertension, prior AMI, prior congestive heart failure, and prior revascularization were higher among diabetic patients, particularly those taking insulin. Diabetic patients, particularly those taking insulin, were less likely to receive aspirin and beta blockers and to undergo coronary revascularization. Diabetic patients had higher 30-day and 1-year mortality than nondiabetic patients. After adjustment for demographics, clinical and hospital characteristics, and treatment strategies, insulin-treated diabetics had the highest risk of mortality, followed by diabetics receiving oral hypoglycemic agents, followed by diet-controlled diabetics. Thus, diabetes is highly prevalent among elderly patients with an AMI. Mortality rates for these patients, particularly insulin-using diabetics, are higher than among their nondiabetic counterparts. Preventive and therapeutic strategies must be developed to ensure improved short- and long-term outcomes for elderly patients with diabetes and AMI.

Diabetes mellitus and outcome after primary coronary angioplasty for acute myocardial infarction: lessons from the GUSTO-IIb Angioplasty Substudy. Global Use of Strategies to Open Occluded Arteries in Acute Coronary Syndromes

OBJECTIVES

We sought to compare the efficacy of primary angioplasty in diabetics versus nondiabetics and to evaluate the relative benefits of angioplasty over thrombolytic therapy among diabetics.

BACKGROUND

Primary angioplasty for myocardial infarction is at least as effective as thrombolytic therapy in the general population. However, the influence of diabetic status on outcome after primary angioplasty versus thrombolysis remains unknown.

METHODS

Patients in the Global Use of Strategies To Open Occluded Arteries in Acute Coronary Syndromes (GUSTO-IIb) Angioplasty Substudy were randomized to receive either primary angioplasty or accelerated alteplase. The interaction of diabetic status (diabetics n = 177, nondiabetics n = 961) and treatment strategy with the occurrence of the primary end point (death, nonfatal reinfarction or nonfatal, disabling stroke at 30 days) was analyzed (power to detect a 40% relative reduction in the primary end point with alpha = 0.05 and beta = 0.20). Among patients who were randomized to and underwent primary angioplasty, procedural success (defined as residual stenosis <50% and TIMI grade 3 flow) was assessed based on diabetic status.

RESULTS

Compared with nondiabetics, diabetics had worse baseline clinical and angiographic profiles. Despite more severe stenosis and poorer flow in the culprit artery, procedural success with angioplasty was similar for diabetics (n = 81; 70.4%) and nondiabetics (n = 391; 72.4%). Outcome at 30 days was better for nondiabetics randomized to angioplasty versus alteplase (adjusted odds ratio, 0.62; 95% confidence interval, 0.41-0.96) with a similar trend for diabetics (0.70, [0.29-1.72]). We noted no interaction between diabetic status and treatment strategy on outcome (p = 0.88).

CONCLUSIONS

Primary angioplasty was similarly successful in diabetics and nondiabetics and appeared to be more effective than thrombolytic therapy among diabetics with acute infarction.

Lack of evidence for secretion of plasminogen activator inhibitor-1 by human subcutaneous adipose tissue in vivo

Circulating plasminogen activator inhibitor-1 (PAI-1) levels are elevated in patients with coronary heart disease and may play an important role in atherothrombosis. Levels are also raised in obese, hypertriglyceridaemic, or insulin-resistant subjects, which predispose people to coronary heart disease. It is unclear, though, which organ is responsible for PAI-1 secretion, either in health or disease. We measured arteriovenous differences across a subcutaneous adipose tissue bed in 25 subjects without coronary heart disease, which, combined with measures of adipose tissue blood flow, provides synthetic rates. There was no net increase in levels of PAI-1 activity (median change 0.23, interquartile range -0.59, 1.21 IU x L(-1), p=0.30) or of PAI-1 antigen (mean change -0.01, SD+/-2.93 ng x mL(-1), p=0.98) in these subjects. Assuming homogeneous production of PAI-1 by all adipose tissue beds, the contribution of adipose tissue to PAI-1 activity is 3.1% (interquartile range, -11.7, +7.0%) and to PAI-1 antigen 1.6% (interquartile range -14.5, +7.3%). Arteriovenous difference of PAI-1 activity and antigen did not relate to measures of obesity, triglyceride, insulin, fatty acids, or circulating concentrations or adipose tissue production of tumour necrosis factor-alpha or interleukin-6. We conclude that, at least in healthy subjects, subcutaneous adipose tissue does not contribute significantly to circulating levels of PAI-1.

Sulfonylurea drugs increase early mortality in patients with diabetes mellitus after direct angioplasty for acute myocardial infarction

OBJECTIVES

The purpose of this study was to examine the impact of sulfonylurea drug use on outcome in diabetic patients undergoing direct coronary angioplasty for acute myocardial infarction.

BACKGROUND

Sulfonylurea drugs impair ischemic preconditioning. Whether sulfonylurea drugs affect outcome adversely in diabetic patients undergoing direct angioplasty for acute myocardial infarction is unknown.

METHODS

Clinical outcomes after direct balloon angioplasty for acute myocardial infarction were evaluated in 67 diabetic patients taking oral sulfonylurea drugs and 118 diabetic patients not taking these drugs.

RESULTS

Hospital mortality was significantly higher among diabetics treated with sulfonylurea drugs at the time of myocardial infarction (24% vs. 11%). Univariate analysis identified sulfonylurea drug, age, ventricular function, ejection fraction less than 40%, prior bypass surgery and congestive heart failure as correlates of increased in-hospital mortality. Logistic regression found sulfonylurea drug use (odds ratio 2.77, p=0.017) to be independently associated with early mortality. Congestive heart failure, but not sulfonylurea drug use, was associated with an increased incidence of in-hospital ventricular arrhythmias. Congestive heart failure, prior bypass surgery and female gender, but not sulfonylurea drug use, were associated with late adverse events.

CONCLUSIONS

Sulfonylurea drug use is associated with an increased risk of in-hospital mortality among diabetic patients undergoing coronary angioplasty for acute myocardial infarction. This early risk is not explained by an increase in ventricular arrhythmias, but may reflect deleterious effects of sulfonylurea drugs on myocardial tolerance for ischemia and reperfusion. For surviving patients sulfonylurea drug use is not associated with an increased risk of serious late adverse events.

The effect of number of days in culture and plasminogen activator inhibitor-1 (PAI-1) 4G/5G genotype on PAI-1 antigen release by cultured human umbilical vein endothelial cells

An insertion/deletion (4G/5G) polymorphism in what has been shown to be an enhancer/repressor binding site in the promoter region of the PAI-1 gene has been related to plasma PAI-1 activity. Transfection studies demonstrated increased interleukin-1 stimulated PAI-1 synthesis in cells containing the 4G sequence. To study this response in endothelial cells, first passage HUVEC from 26 umbilical cords were stimulated with interleukin-1 and tumor necrosis factor-alpha. PAI-1 antigen was measured in 24-hour conditioned medium and allele-specific PCR utilized to determine genotype at the 4G/5G locus. Analysis of covariance was used to determine whether the effect of a variable time in culture was masking a difference between genotypes. A trend towards higher PAI-1 levels with increasing time in culture was observed. The geometric mean (95% confidence interval) of the basal rate of PAI-1 release was, 4G/4G 9.7 (7.0, 13.5) ng/24 hours (n=11), 4G/5G 9.5 (6.5, 13.9) ng/24 hours (n=9), and 5G/5G 10.9 (7.8, 15.1) ng/24 hours (n=6). In cells of the same cultures, the interleukin-1 stimulated levels were 25.9 (23.1, 29.1), 27.2 (23.6, 31.3), and 23.1 (19.5, 27.3) ng/24 hours, respectively, corresponding to ratios of stimulated to basal levels of 2.68, 2.87, and 2.12. After adjustment for time in culture the basal PAI-1 release was 4G/4G 10.7, 4G/5G 9.1, and 5G/5G 9.7 ng/24 hours. For interleukin-1 stimulated release the adjusted levels were 26.3, 27.0, and 22.7 ng/24 hours, respectively. Adjusted levels in 4G/4G genotype cells were non-significantly greater than those in cells of 5G/5G genotype by a factor of 1.16 (0.95, 4.08). This study did not demonstrate a significant difference in basal or cytokine stimulated PAI-1 release from cells of different PAI-1 promoter (4G/5G) genotypes but does not exclude increased interleukin-1 stimulated PAI-1 release in the 4G/4G compared with the 5G/5G genotype.

Pretreatment plasminogen activator inhibitor-1 (PAI-1) levels and the outcome of thrombolysis with streptokinase in patients with acute myocardial infarction

BACKGROUND

The risk for reinfarctions and delays in reperfusion after streptokinase therapy may be caused by the antifibrinolytic effect of platelet-derived type 1 plasminogen activator inhibitor (PAI-1). This study aims to show the relation of pretreatment PAI-1 levels of patients with acute myocardial infarction treated with streptokinase therapy and the outcome of fibrinolysis, with the emphasis on reperfusion and reinfarction.

METHODS

Pretreatment PAI-1 levels of 60 patients with acute myocardial infarction, treated with streptokinase, were determined by the chromogenic method. Failure of thrombolysis with streptokinase was present when reperfusion was delayed as assessed by noninvasive reperfusion criteria, or reinfarctions developed.

RESULTS

Mean pretreatment PAI-1 level of patients was 6.3+/-1.2 U/ml; span 1.2 U/ml to 34.0 U/ml. Thrombolysis with streptokinse failed significantly in patients with pretreatment PAI-1 levels >4.0 U/ml (p < 0.05), mainly because of significant occurrence of reinfarction (p < 0.05), but less to delayed reperfusion (p > 0.05).

CONCLUSION

Failure of thrombolysis with streptokinase is significantly associated with pretreatment PAI-1 levels of >4.0 U/ml.

[Heart pathology of extracardiac origin. XI. Cardiac repercussions of diabetes mellitus]

Diabetes mellitus is one of the diseases with the greatest risk of developing coronary disease (CD), with the estimation of this risk in relation to the general population being from 2 to 4-fold greater. The existence of diabetes worsens the prognosis of CD and thus, postinfarction mortality in these patients is double that observed in non-diabetic patients. Together with the risk factors found in the general population, those of special interest are those derived from diabetes itself, such as hyperglycemia, dyslipemia, coagulation disorders and hyperinsulinemia or insulin resistance. Among these, the most important is probably the hyperglycemia which may contribute to the appearance of CD by different mechanisms such as proteic glycosylation, accumulation of sorbitol, increase in the synthesis of protein kinase C or oxidative stress. It must not be forgotten that an old controversy has recently been brought up suggesting that sulphonylureas may have a certain cardiotoxic effect, probably acting on the potassium channels dependent on ATP. Acute myocardial infarction in diabetic patients carries a greater risk of congestive heart failure, recurrent infarction, arrhythmia and cardiogenic shock, with one of its characteristics being the possibility of being silent when autonomic neuropathy is present. The prognosis of CD may be markedly improved by obtaining optimum glycemic control during the hours following infarction using intensified treatment. Diabetic myocardiopathy as a differentiated nosology responsible for alterations in myocardial contractile function and greater prevalence of heart failure in these patients seems to be clearly demonstrated although its etiology remains unknown.

Effect of troglitazone on fibrinolysis and activated coagulation in patients with non-insulin-dependent diabetes mellitus

The objective of this study was to determine if treatment of non-insulin-dependent diabetes mellitus (NIDDM) patients with the "insulin sensitizer" troglitazone, both as monotherapy and in combination with insulin, corrects the impaired fibrinolysis and activated coagulation associated with NIDDM. Patients participating in two clinical trials comparing troglitazone and placebo in patients with NIDDM were studied at the time of randomization and after 26 weeks of treatment. Eighteen patients were treated with troglitazone (ten in combination with insulin and eight as monotherapy) and eight were treated with placebo (four in each trial). Plasma concentrations of plasminogen activator inhibitor (PAI-1), prothrombin fragment F1+2, fibrinogen, and von Willebrand Factor (vWF) activity were measured. Plasma PAI-1 concentrations fell significantly from a mean of 68.8 +/- 32.3 ng/mL to 40.4 +/- 20.4 in the troglitazone treated group, but did not change significantly in the placebo treated group. Plasma PAI-1 concentrations were elevated in 15 patients treated with troglitazone and fell to normal in eight of them. There was no significant change in plasma F1+2, vWF, and fibrinogen, but plasma C-peptide and triglyceride concentrations fell significantly with troglitazone. This study demonstrates that troglitazone treatment is associated with a significant fall in plasma PAI-1 antigen concentrations in patients with NIDDM and, therefore, may have a beneficial effect on fibrinolysis.

Influence of diabetes mellitus on clinical outcome in the thrombolytic era of acute myocardial infarction. GUSTO-I Investigators. Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries

OBJECTIVES

This study was undertaken to define and better understand the characteristics and outcomes of patients with diabetes treated for acute myocardial infarction with contemporary thrombolysis.

BACKGROUND

Although thrombolysis has substantially improved survival of patients with myocardial infarction, diabetes mellitus remains an independent predictor for a poor prognosis.

METHODS

We characterized the contemporary relation between diabetes and outcome after myocardial infarction treated with thrombolytic agents from a large international cohort. Of 41,021 patients randomized to receive accelerated tissue-type plasminogen activator (t-PA), streptokinase or a combination of both agents in the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries study, there were 5,944 patients with diabetes and 34,888 patients without diabetes.

RESULTS

Patients with diabetes were older and more likely to be female, to present with anterior wall infarction, to receive thrombolysis later and to have triple-vessel coronary artery disease. Mortality at 30 days was highest among diabetic patients treated with insulin (12.5%) compared with non-insulin-treated diabetic (9.7%) and nondiabetic (6.2%) patients (p < 0.001). Mortality was lowest among those with diabetes receiving accelerated t-PA, which is consistent with the results of the overall patient cohort. Although stroke occurred more frequently among diabetic (1.9%) than nondiabetic patients (1.4%, p < 0.001), there was no significant difference in the rates of intracranial hemorrhage. Cardiac failure, shock, atrioventricular block and atrial flutter/ fibrillation were more common among diabetic patients. The proportion of patients undergoing revascularization was similar between patients with and without diabetes, although diabetic patients were more likely to undergo coronary artery bypass graft surgery (10.4% vs. 8.3%). Diabetes remained an independent predictor for mortality at 1-year follow-up (14.5% vs. 8.9%, p < 0.001).

CONCLUSIONS

Diabetes, alone and in association with its comorbidities, portends a substantially worse 30-day and 1-year prognosis for patients with myocardial infarction.

The Deidesheimer meeting: significance of classical and new risk factors in non-insulin-dependent diabetes mellitus

The major risk factors appear to explain only a small proportion of the excess risk of coronary heart disease in patients with Non-Insulin-Dependent Diabetes Mellitus (NIDDM). Among novel risk markers that have been-proposed to explain the susceptibility of NIDDM subjects to coronary heart disease are insulin resistance, elevated concentrations of proinsulin-line molecules, plasminogen activator inhibitor, and microalbuminuria. Several prospective studies have shown that hyperinsulinemia predicts coronary heart disease, perhaps independently of established risk factors. Some of this excess risk may be through the dyslipidemia, or the elevation in activity of plasminogen activator inhibitor, an inhibitor of fibrinolysis, which relate to hyperinsulinemia. However proinsulin-like molecules show similar relationships with both risk factors and with prevalent coronary heart disease as does insulin, despite low concentrations of these molecules in the circulation, suggesting a causative relationship is improbable. Furthermore, the link between insulin resistance and microalbuminuria, a powerful predictor of vascular disease in its own right, is poorly understood through known mechanisms. This clustering leads to the possibility of a link with coronary heart disease through other mechanisms. It is proposed that the pathogenesis of this link is endothelial dysfunction, which may predicate both impaired insulin action, through effects of blood flow and insulin transport, and the associated dyslipidemia, impaired fibrinolysis, microalbuminuria, and atherogenesis. In terms of etiology, the links of all these risk factors with evidence of growth retardation in early life may suggest a role of the thirfty phenotype hypothesis-impaired organogenesis resulting from poor maternal nutrition during pregnancy.

Angiographic findings and outcome in diabetic patients treated with thrombolytic therapy for acute myocardial infarction: the GUSTO-I experience

OBJECTIVES

This study sought to determine whether diabetes mellitus, in the setting of thrombolysis for acute myocardial infarction, affects 1) early infarct-related artery patency and reocclusion rates; and 2) global and regional ventricular function indexes. We also sought to assess whether angiographic or baseline clinical variables, or both, can account for the known excess mortality after myocardial infarction in the diabetic population.

BACKGROUND

Mortality after acute myocardial infarction in patients with diabetes is approximately twice that of nondiabetic patients. It is uncertain whether this difference in mortality is due to a lower rate of successful thrombolysis, increased reocclusion after successful thrombolysis, greater ventricular injury or a more adverse angiographic or clinical profile in diabetic patients.

METHODS

Patency rates and global and regional left ventricular function were determined in patients enrolled in the GUSTO-I Angiographic Trial. Thirty-day mortality differences between those with and without diabetes were compared.

RESULTS

The diabetic cohort had a significantly higher proportion of female and elderly patients, and they were more often hypertensive, came to the hospital later and had more congestive heart failure and a higher number of previous myocardial infarctions and bypass surgery procedures. Ninety-minute patency (Thrombolysis in Myocardial Infarction [TIMI] flow grade 3) rates in patients with and without diabetes were 40.3% and 37.6%, respectively (p = 0.7). Reocclusion rates were 9.2% vs. 5.3% (p = 0.17). Ejection fraction at 90 min after thrombolysis was similar in diabetic and nondiabetic patients ([mean +/- SEM] 6.10 +/- 1.6% vs. 60.1 +/- 0.7%, p = 0.7), as was regional ventricular function (number of abnormal chords: 19.1 +/- 2.0 vs. 17.5 +/- 0.8, p = 0.3; SD/chord: -2.3 +/- 0.2 vs. -2.4 +/- 0.1, p = 0.6). Diabetic patients had less compensatory hyperkinesia in the noninfarct zone (SD/ chord: 1.3 +/- 0.2 vs. 1.7 +/- 0.1, p < or = 0.01). No significant difference in ventricular function was noted at 5- to 7-day follow-up. The 30-day mortality rate was 11.3% in diabetic versus 5.9% in nondiabetic patients (p < or = 0.0001). After adjustment for clinical and angiographic variables, diabetes remained an independent determinant of 30-day mortality (p = 0.02).

CONCLUSIONS

Early (90-min) infarct-related artery patency as well as regional and global ventricular function do not differ between patients with and without diabetes after thrombolytic therapy, except for reduced compensatory hyperkinesia in the noninfarct zone among patients with diabetes. Diabetes remained an independent determinant of 30-day mortality after correction for clinical and angiographic variables.

Hyperinsulinaemia, insulin resistance, microalbuminuria and the risk of coronary heart disease

In population studies both hyperinsulinaemia, a marker for insulin resistance, and microalbuminuria have been shown to predict coronary heart disease. Insulin resistance clusters with several standard cardiovascular risk factors, as well as with abnormalities of fibrinolysis, with small, dense, low-density lipoprotein patterns, and with elevated concentrations of proinsulin-like molecules. This makes the independence of the relationship with coronary heart disease difficult to disentangle. Microalbuminuria is associated with a number of abnormalities of risk factors, but the relationship with coronary heart disease does not appear to be explained by these associations. The two conditions, insulin resistance and microalbuminuria, are associated, and together appear to be a very powerful predictor of cardiovascular risk. There is evidence that endothelial dysfunction may lead to impaired insulin action, as well as to capillary albumin leak, and the proposal is made that these associations, with each other and with coronary heart disease, are features of a common antecedent. The role of growth retardation in endothelial function, and in determining cardiovascular risk in adulthood is a subject of intense interest.

Cardiovascular mortality and morbidity in type-2 diabetes mellitus

A representative number of prospective studies clearly indicate that cardiovascular morbidity and mortality is significantly increased in type-2 diabetic patients in comparison with non-diabetic control subjects. The cardiovascular death rate is 4.4 fold increased in those diabetic patients presenting none of the classical risk factors (hypertension, hypercholesterinemia or smoking) compared with age-matched control subjects (MRFIT). A decreased survival rate after myocardial infarction, congestive heart failure and an increased occurrence of silent ischemia are responsible for the poor prognosis of type-2 diabetic patients. Recent studies indicate that haemostatic abnormalities and endothelial dysfunction are important risk factors for coronary events in diabetic as well as in nondiabetic patients. In newly diagnosed type-2 diabetic patients a similar prevalence of myocardial infarction and angina compared to previously known type-2 diabetes was found. The long prediabetic period and clustering of risk factors may be very relevant for the high prevalence of cardiovascular disease already at diagnosis of type-2 diabetes. More recent studies performed in Scotland and Verona demonstrated a mortality risk approximately only 50% higher than in nondiabetic subjects. The reduction in the mortality risk could reflect an improvement in diabetes prognosis from the 1960s to the 1980s. Recent observations in type-2 diabetic patients from Finland indicate that glycemic control is an important predictor for coronary heart disease morbidity and mortality. However incidence of coronary heart disease is only low in those patients presenting with a HbAlc value below 6.0%. More information will be available after analysis of the United Kingdom prospective diabetes study. (UKPDS).

Heart disease in diabetes mellitus

The spectrum of heart disease in diabetic patients is broad and complex. This article discusses the epidemiologic associations between the two causes. It attempts to summarize the effects of diabetes at the cellular, vascular, and myocardial levels. The clinical manifestations are explored, and the treatment of heart disease as it pertains to diabetic patients is discussed.

Coronary heart disease in diabetes mellitus: three new risk factors and a unifying hypothesis

The standard risk factors--dyslipidaemia, hypertension and smoking--provide little help in explaining the raised cardiovascular risk in diabetes. It can be calculated that intervening for disturbances of these risk factors could do little to rectify the loss of life expectancy of around 10 years for a middle-aged diabetic man. Three new risk factors are discussed, which together may contribute to some of the excess cardiovascular risk in diabetes. Plasminogen activator inhibitor is an inhibitor of fibrinolysis which is elevated in concentration in diabetic subjects, and may increase both the incidence of thrombotic events and the risk of reinfarction after the initial infarct. Recent work also suggests that high activity of this substance may impair pharmacological fibrinolysis. Proinsulin-like molecules are elevated in concentration in diabetic patients and correlate with levels of a number of other risk factors. Whilst these correlations may represent cause and effect for plasminogen activator inhibitor, there is no evidence that changes in levels of proinsulin-like molecules influence levels of other risk factors. Microalbuminuria provides a powerful indicator of cardiovascular risk in both diabetic and non-diabetic subjects, but whilst the mechanisms for this association are unclear, they are again unlikely to be mediated through changes in levels of standard risk factors. Recent observations of an association between short stature and microalbuminuria suggest that intrauterine or early infant nutrition may represent a common antecedent, these having also been shown to predict both components of the insulin resistance syndrome and cardiovascular disease in adult life.