Diabetes mellitus is a strong negative prognostic factor in patients with myocardial infarction treated with thrombolytic therapy

Acute coronary syndromes in diabetic patients, outcome, revascularization, and antithrombotic therapy

Diabetes exacerbates the progression of atherosclerosis and is associated with increased risk of developing acute coronary syndrome (ACS). Approximatively 25-30% of patients admitted for ACS have diabetes. ACS occurs earlier in diabetics and is associated with increased mortality and a higher risk of recurrent ischemic events. An increased proinflammatory and prothrombotic state is involved in the poorer outcomes of diabetic patients. In the past decade advancement in both percutaneous coronary intervention (PCI) and coronary artery by-pass graft (CABG) techniques and more potent antiplatelet drugs like prasugrel and ticagrelor improved outcomes of diabetic patients with ACS, but this population still experiences worse outcomes compared to non-diabetic patients. While in ST elevation myocardial infarction urgent PCI is the method of choice for revascularization, in patients with non-ST elevation ACS an early invasive approach is suggested by the guidelines, but in the setting of multivessel (MV) or complex coronary artery disease (CAD) the revascularization strategy is less clear. This review describes the accumulating evidence regarding factors involved in promoting increased incidence and poor prognosis of ACS in patients with diabetes, the evolution over time of prognosis and outcomes, revascularization strategies and antithrombotic therapy studied until now.

High plasma concentrations of autoantibodies against native peptide 210 of apoB-100 are related to less coronary atherosclerosis and lower risk of myocardial infarction

AIMS

We examined whether antibodies against peptides 45 and 210 of apoB-100 are related to myocardial infarction (MI) and severity of coronary atherosclerosis.

METHODS AND RESULTS

Three hundred and eighty-seven survivors of a first MI (aged <60 years) and 387 sex- and age-matched controls were characterized in detail. IgG and IgM autoantibodies against native and malondialdehyde (MDA)-modified peptides 45 and 210 of apoB-100 (amino acids 661-680 and 3136-3155) were quantified in plasma and quantitative coronary angiography was performed in 243 patients. Post-infarction patients had significantly lower IgG against the native peptide 210 (IgG-p210(nat)) and higher IgM against the MDA-modified peptide 210 (IgM-p210(MDA)) compared with controls, whereas no differences were found for other antibodies. Plasma concentrations of IgG-p210(nat), but not IgM-p210(MDA), were independently and inversely related to the degree of coronary atherosclerosis in patients. In multiple logistic regression analysis (including established risk indicators), MI risk was 0.55 (95%CI: 0.37-0.81) for individuals in the IgG-p210(nat) upper quartile compared with the remaining individuals.

CONCLUSION

Circulating IgG antibodies against the native peptide 210 of apoB-100 are inversely related to the severity of coronary atherosclerosis and associated with lower risk of MI. Epitope 210 of apoB-100 emerges as a target for immunization against atherosclerosis in humans.

Lower serum concentration of matrix metalloproteinase-3 in the acute stage of myocardial infarction

OBJECTIVES

The importance of matrix metalloproteinases (MMPs) in the progression and rupture of the atherosclerotic plaque is gaining increasing recognition but the mechanisms are not yet fully understood. The aim of this study was to investigate the significance of MMP-3 in the acute phase of myocardial infarction (MI) and the influence of the -1612 5A/6A MMP-3 gene promoter polymorphism on serum MMP-3 concentration.

SUBJECTS

One-hundred and sixty-four patients admitted with ST-elevation MI and receiving thrombolysis treatment were included in this study. Serum MMP-3 was analysed at admission, after 48 h and at 3 months.

RESULTS

Serum MMP-3 concentration was significantly increased at 3 months when compared with admission and 48 h (19.5 ng mL(-1) [14.4-24.7] vs. 15.5 ng mL(-1) [10.5-21.8] at admission, P < 0.001; and 14.7 ng mL(-1) [9.9-23.8] at 48 h, P < 0.001). Furthermore, we found the -1612 5A/6A polymorphism to influence the serum concentration of MMP-3 at all time-points: 14.1 ng mL(-1) [10.2-18.8] in 5A/5A; 19.6 ng mL(-1) [15.0-24.4] in 5A/6A; and 24.0 ng mL(-1) [20.1-32.3] in 6A/6A genotype at 3 months (P < 0.001 between all groups). Female patients had lower serum MMP-3 concentration than male patients at all time-points (14.8 ng mL(-1) [9.4-20.8] vs. 19.9 ng mL(-1) [16.0-26.9], P < 0.0001 at 3 months).

CONCLUSIONS

Serum concentration of MMP-3 is significantly lower in the acute stage of MI than during recovery and is significantly influenced by -1612 5A/6A genotype and gender. Together with previous findings, these results primarily implicate MMP-3 in atherosclerosis progression rather than in acute MI.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

The impact of diabetes or elevated fasting blood glucose on cardiovascular prognosis in patients with stable angina pectoris

AIMS

To examine the influences of diabetes and elevated fasting blood glucose on cardiovascular prognosis in patients with stable angina pectoris.

METHODS

In a prospective study of 809 patients with stable angina pectoris randomized to receive metoprolol or verapamil, a subgroup of 69 diabetic patients was compared with non-diabetic patients with respect to the risk of cardiovascular (CV) death, non-fatal myocardial infarction (MI) and revascularization. We also analysed a subgroup of 67 patients with fasting blood glucose > or = 6.1 mmol/l, defined according to the most recent revised guidelines for the diagnosis of diabetes mellitus. Fasting blood glucose was measured in venous whole blood at baseline.

RESULTS

The diabetic patients had a greater risk-factor burden, with a higher prevalence of hypertension, more likely to be male, a tendency towards a higher prevalence of previous MI, and higher triglyceride and lower high-density lipoprotein (HDL)-cholesterol levels. In multivariate analyses, diabetes was an independent risk factor for CV events with a relative risk of 2.64 (CI 1.39-5.00; P < 0.001) for CV death/MI, and 1.79 (CI 1.02-3.15; P < 0.01) for revascularization. Blood glucose > or = 6.1 mmol/l without a diagnosis of diabetes mellitus was found in 67 patients, and predicted CV death/MI [relative risk 2.76 (CI 1.97-3.84)] in both univariate and multivariate analyses. The prognosis of diabetic or hyperglycaemic patients did not differ significantly with metoprolol compared with verapamil treatment.

CONCLUSIONS

Diabetes mellitus is an independent risk factor for CV death/MI and for revascularization in patients with stable angina pectoris. Elevated fasting blood glucose was seen in 9% of patients without known diabetes and was an equally strong and independent risk factor for CV death/MI as diagnosed and treated diabetes.

Plasma C-Reactive Protein and Lipoprotein Levels, and Progression of Coronary Artery Disease after Myocardial Infarction Treated with Thrombolysis

BACKGROUND

There is a paucity of studies using quantitative coronary angiography (QCA) to determine progression of coronary artery disease (CAD) after an acute coronary event. Furthermore, despite a great interest in effects of inflammation and 'early' lipid lowering therapy, no data have been published on the role of plasma C-reactive protein (CRP) and lipoprotein levels in CAD progression after myocardial infarction.

METHODS

Seventy-two patients with myocardial infarction treated with thrombolysis, but not with statins, were investigated with QCA during admission and after 6 months. Plasma CRP concentrations were measured by a high sensitive method 2 days after the acute event, and plasma high-sensitive CRP and lipoprotein levels were determined 3 months after myocardial infarction.

RESULTS

Overall, there was no significant progression of CAD, but when stenoses were grouped into those reducing the lumen diameter greater or less than 50%, progression was seen in stenoses originally <50%, whereas regression was seen in stenoses >50%. No consistent associations were seen between plasma CRP, lipoprotein lipid or lipoprotein(a) levels and CAD.

CONCLUSIONS

Progression of stenoses <50% might be of clinical importance since these stenoses are more prone to rupture. Furthermore, the lack of associations between change in minimum lumen diameter and plasma CRP and lipoprotein concentrations suggests that positive effects on CAD progression of early treatment with anti-inflammatory or lipid-lowering drug therapy may not be expected in this subset of patients.

A novel common single nucleotide polymorphism in the promoter region of the C-reactive protein gene associated with the plasma concentration of C-reactive protein

The plasma CRP concentration has consistently been shown to be associated with the risk of future coronary heart disease (CHD) and recent studies have suggested that CRP has a pathogenic role in CHD. Family studies and genotype-phenotype association studies of known polymorphisms in the intron, second exon and 3'-untranslated region (UTR) have suggested that plasma CRP concentrations are under genetic control. However, no functional polymorphisms have so far been reported in the promoter region of the CRP gene. Screening of 1600 base pair (bp) of the promoter region of the CRP gene, using denaturing high performance liquid chromatography, revealed two novel common single nucleotide polymorphisms (SNPs). One of them, a three allelic SNP located at position -286 from the transcription start, was strongly associated with the plasma CRP concentration, predominantly in patients with CHD. No difference in allele frequency was seen between middle-aged post-infarction patients and population-based controls. The prognostic role and therapeutic implications in CHD and the functionality of this polymorphism remain to be determined.

Prognostic value of plasma interleukin-6 concentrations and the -174 G > C and -572 G > C promoter polymorphisms of the interleukin-6 gene in patients with acute myocardial infarction treated with thrombolysis

The present study was performed to investigate the prognostic value of plasma interleukin-6 (IL-6) concentrations and promoter polymorphisms of the IL-6 gene in patients with acute myocardial infarction treated with thrombolysis. Two hundred and eight patients with myocardial infarction treated with thrombolysis were included and followed for 2-5 years. Plasma concentrations of IL-6 were measured at admission and 48 h after admission. Genotyping for the -174 G > C and -572 G > C IL-6 polymorphisms was performed. Patients who died of cardiovascular causes or suffered a new myocardial infarction during follow-up had increased plasma concentrations of IL-6 at admission (P < 0.002) and at 48 h after admission (P < 0.05) compared with patients who had an uneventful course. IL-6 levels above the median at admission were independently associated with a worse prognosis. No associations were found between IL-6 levels and the promoter polymorphisms. The -174 G > C polymorphism was not associated with cardiovascular death or a new myocardial infarction, whereas the -572 G > C polymorphism showed a borderline significant increase in risk (P = 0.05) in univariate analysis. In conclusion, the early IL-6 response during myocardial infarction is associated with prognosis in patients with Q-wave myocardial infarction, whereas no associations were found between IL-6 genotype and phenotype.

Type 2 diabetes and intravenous thrombolysis outcome in the setting of ST elevation myocardial infarction

OBJECTIVE

There are conflicting results regarding the impact of type 2 diabetes on intravenous thrombolysis effectiveness during ST elevation myocardial infarction (STEMI). The present study, using a continuous 12-lead electrocardiogram, examined the possible association of type 2 diabetes with both acute intravenous thrombolysis effectiveness and long-term prognosis in this setting.

RESEARCH DESIGN AND METHODS

The study included 726 consecutive subjects (214 type 2 diabetic subjects) with STEMI who received intravenous thrombolysis in the first 6 h from index pain and were followed up for 3.5 years.

RESULTS

Type 2 diabetic subjects had significantly lower incidence of sustained > or = 50% ST recovery than nondiabetic subjects (P = 0.03). Additionally, the former required a significantly greater time interval through the achievement of this criterion than the latter (P < 0.001). In both type 2 diabetic (P < 0.001) and nondiabetic subjects (P < 0.001), those who had not attained > or = 50% ST recovery were at significantly higher risk of cardiac death than subjects who had reached this criterion. The subjects who attained the above electrocardiographic criterion in > or = 60 min after thrombolysis initiation were at significantly higher risk compared with those who achieved this criterion in <60 min (P = 0.02). However, this association was true only for type 2 diabetic subjects (P = 0.01) and not for nondiabetic subjects (P = 0.9).

CONCLUSIONS

The present study suggests that type 2 diabetes is a strong predictor of acute intravenous thrombolysis failure during STEMI. This finding may significantly contribute to the worse prognosis for type 2 diabetic subjects compared with nondiabetic ones in this setting.

Prognostic value of plasma C-reactive protein and fibrinogen determinations in patients with acute myocardial infarction treated with thrombolysis

OBJECTIVES

To investigate the prognostic value of plasma C-reactive protein (CRP) and fibrinogen determinations in patients with acute myocardial infarction treated with thrombolysis.

DESIGN

Longitudinal study of morbidity and mortality.

SETTING

Coronary care unit at Danderyd Hospital, Stockholm, Sweden.

SUBJECTS

A total of 222 patients aged 75 years or below, treated with thrombolysis because of typical symptoms of myocardial infarction and electrocardiogram showing ST-segment elevation or bundle branch block were included in the study. The patients were followed for 24-60 months (mean 40 +/- 16 months).

MAIN OUTCOME MEASURES

Cardiovascular death or new myocardial infarction.

RESULTS

Concentrations of CRP were significantly higher at 48 h than at 3 months, whilst the levels of fibrinogen were similar. CRP and fibrinogen concentrations measured during the acute phase of myocardial infarction were associated with cardiovascular death or a new myocardial infarction during follow-up in univariate analysis. CRP levels measured 3 months after the acute event were not associated with subsequent events whereas fibrinogen concentrations showed a borderline prognostic significance (P = 0.05). When CRP and fibrinogen were entered into multivariate analysis together with the previously established prognostic factors in the patient group (age, diabetes mellitus and left ventricular function), these markers of inflammation did not add further prognostic information.

CONCLUSION

C-reactive protein and fibrinogen do not carry the same independent prognostic information after acute myocardial infarction treated with thrombolysis as in studies previously reported for patients with unstable angina or non-Q-wave myocardial infarction.

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).

C-reactive protein levels on admission are associated with response to thrombolysis and prognosis after ST-segment elevation acute myocardial infarction

BACKGROUND

Several studies have shown the independent association of high plasma C-reactive protein (CRP) levels with an adverse prognosis in patients with acute myocardial infarction. However, the possible association of plasma CRP levels with response to thrombolysis and short- and long-term cardiac mortality has not been investigated. The aim of this study was to evaluate these possible associations.

METHODS

Three hundred nineteen consecutive patients who received intravenous thrombolysis because of ST-segment elevation acute myocardial infarction were prospectively studied. Patients were classified according to tertiles of plasma CRP levels on admission.

RESULTS

Patients at the top tertile had a significantly lower incidence of complete ST-segment resolution (third vs first, P <.001, third vs second, P =.009) or Thrombolysis In Myocardial Infarction (TIMI) 3 flow in the infraction-related artery (third vs first, P <.001, third vs second, P =.02), more compromised left ventricular function (third vs first, P =.02, second vs third, P =.04), greater inhospital mortality (third vs first, P =.03, third vs second, P =.06), and greater 3-year cardiac mortality (third vs first, P =.01, third vs second, P =.07).

CONCLUSIONS

Plasma levels of CRP on admission may be a predictor of reperfusion failure and of short- and long-term prognosis in patients with ST-segment elevation acute myocardial infarction.