Clinical and economic impact of diabetes mellitus on percutaneous and surgical treatment of multivessel coronary disease patients: insights from the Arterial Revascularization Therapy Study (ARTS) trial

CARBOHYDRATE METABOLISM DISORDERS AND CORONARY HEART DISEASE: PROGNOSTIC VALUE AND REVASCULARISATION EFFECTIVENESS

This literature review presents the data on the prevalence and prognostic value of carbohydrate metabolism disorders, such as Type 2 diabetes mellitus (DM) and pre-diabetes — fasting hyperglycaemia and impaired glucose tolerance), among patients with coronary heart disease (CHD). The authors present the results of large studies on comparative effectiveness of modern pharmacological treatment and myocardial revascularisation (percutaneous coronary intervention and coronary artery bypass graft surgery) in patients with CHD and DM. 

Effect of normalization of fasting glucose by intensified insulin therapy and influence of eNOS polymorphisms on the incidence of restenosis after peripheral angioplasty in patients with type 2 diabetes: a randomized, open-label clinical trial

Primary objective was to evaluate whether an intensified insulin therapy (IIT) incorporating the target of normal fasting glucose and HbA1c levels could halve the incidence of restenosis/amputation/SCA/death at 6 months after peripheral angioplasty compared with standard care (SC) in patients with type 2 diabetes (DMT2) affected by critical limb ischemia (CLI). Forty-six consecutive patients with DMT2 and CLI were randomly assigned to a parallel, open-label study with IIT (basal-bolus glulisine + glargine administrations) or SC (glargine administration + oral antidiabetic drugs). A SNP of eNOS (rs753482-A>C) and circulating CD34(+) and CD34(+)KDR(+) progenitor cells were determined. At the end of the study, although HbA1c levels were lower in IIT than in SC (6.9 ± 1.3 % vs. 7.6 ± 1.2 %, p < 0.05), IIT did not reduce the cumulative incidence of restenosis/amputation/SCA/death (52 and 65 %, respectively, odd ratio 0.59; CI 95 %: 0.21-1.62, p = 0.59). rs753482AC+CC as compared with rs753482AA increased the cumulative incidence of restenosis/amputation/SCA/death (79 and 42 %; odd ratio 5.3; CI 95 %: 1.41-19.5, p < 0.02). Baseline CD34(+)KDR(+) were higher in rs753482AA (166.2 ± 154.0 × 10(6) events) than in rs753482AC+CC (63.1 ± 26.9 × 10(6) events, p < 0.01). At the end of the study, the highest circulating CD34(+)KDR(+) were found in IIT rs753482AA (246.9 ± 194.0 × 10(6) events) while the lowest levels were found in SC rs753482AC+CC (70.9 ± 45.0 × 10(6) events). IIT did not decrease the cumulative incidence of restenosis/amputation/SCA/death in DMT2 and CLI patients. These patients correspond to a class of fragile subjects at high risk of cardiovascular events, and new predictors of restenosis should be contemplated, such as of eNOS polymorphism, (rs753482-A>C SNP) and circulating endothelial progenitor cells.

The STS score is the strongest predictor of long-term survival following transcatheter aortic valve implantation, whereas access route (transapical versus transfemoral) has no predictive value beyond the periprocedural phase

OBJECTIVES

Transcatheter aortic valve implantation (TAVI) was developed as a promising new therapy for inoperable and surgical high-risk patients as an alternative to traditional aortic valve replacement. After a successful procedure, prognosis may mainly be determined by comorbidities. However, no appropriate risk score to predict long-term outcome following TAVI is currently available. The aim of this study was to identify predictors of adverse short- and long-term outcomes.

METHODS

This is a two-centre registry study including a total of 426 TAVI procedures (274 transfemoral [TF] and 152 transapical [TA]) performed at the University Hospital and CardioVascular Center of Frankfurt (Germany) between 2005 and 2011.

RESULTS

Observed 30-day mortality was 4.8% among TF and 12.6% among TA patients (hazard ratio [HR] TF vs TA was 0.38; 95% confidence interval [CI] 0.19-0.77). Patients with a higher Society of Thoracic Surgeons (STS) score experienced a 6% elevation in the 30-day mortality per point (HR 1.06; 95% CI 1.03-1.10), whereas the predictive value of the logistic EuroSCORE (HR 1.03; 95% CI 1.01-1.05) and EuroSCORE 2 (HR 1.04; 95% CI 1.01-1.07) was slightly lower. Most interestingly, older age (>80 years) and the access type were predictors of 30-day mortality. However, the only independent predictor of long-term mortality in a 30-day landmark analysis was the STS score (HR 1.05; 95% CI 1.02-1.09).

CONCLUSIONS

The STS score outperforms the logistic EuroSCORE in predicting adverse outcomes following TAVI. The transapical approach is associated with higher perioperative mortality, but does not exert any influence on long-term prognosis beyond the periprocedural phase.

Cost-effectiveness of percutaneous coronary intervention with drug eluting stents versus bypass surgery for patients with diabetes mellitus and multivessel coronary artery disease: results from the FREEDOM trial

BACKGROUND

Studies from the balloon angioplasty and bare metal stent eras have demonstrated that coronary artery bypass grafting (CABG) is cost-effective compared with percutaneous coronary intervention (PCI) for patients undergoing multivessel coronary revascularization-particularly among patients with complex coronary artery disease or diabetes mellitus. Whether these results apply in the drug-eluting stent (DES) era is unknown.

METHODS AND RESULTS

Between 2005 and 2010, 1900 patients with diabetes mellitus and multivessel coronary artery disease were randomized to PCI with DES (DES-PCI; n=953) or CABG (n=947). Costs were assessed from the perspective of the U.S. health care system. Health state utilities were assessed using the EuroQOL 5 dimension 3 level questionnaire. A patient-level microsimulation model based on U.S. life-tables and in-trial results was used to estimate lifetime cost-effectiveness. Although initial procedural costs were lower for CABG, total costs for the index hospitalization were $8622 higher per patient. Over the next 5 years, follow-up costs were higher with PCI, owing to more frequent repeat revascularization and higher outpatient medication costs. Nonetheless, cumulative 5-year costs remained $3641 higher per patient with CABG. Although there were only modest gains in survival with CABG during the trial period, when the in-trial results were extended to a lifetime horizon, CABG was projected to be economically attractive relative to DES-PCI, with substantial gains in both life expectancy and quality-adjusted life expectancy and incremental cost-effectiveness ratios <$10 000 per life-year or quality-adjusted life-year gained across a broad range of assumptions regarding the effect of CABG on post-trial survival and costs.

CONCLUSIONS

Despite higher initial costs, CABG is a highly cost-effective revascularization strategy compared with DES-PCI for patients with diabetes mellitus and multivessel coronary artery disease.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinical-trials.gov. Unique identifier: NCT00086450.

Outcomes of coronary revascularization (percutaneous or bypass) in patients with diabetes mellitus and multivessel coronary disease

Clinical outcomes in patients with diabetes mellitus and multivessel disease (MVD) undergoing coronary revascularization have not been extensively evaluated, we sought to examine outcomes in a diabetic cohort of 195 consecutive patients with MVD characterized by SYNTAX scores (SSs) undergoing nonrandomized revascularization, 102 (52%) by percutaneous intervention (PCI) and 93 (48%) by coronary artery bypass grafting (CABG) at Liverpool Hospital (Sydney, Australia) from June 2006 to March 2010. Clinical outcomes were assessed at a median term of 14 months. The overall median SS was 44, with significantly higher SSs in CABG- than PCI-treated patients (48 vs 39, p <0.0001). There was a similar incidence of all-cause death, nonfatal myocardial infarction and stroke in PCI- and CABG-treated patients (6.1% vs 8.3%, p = 0.383; 12% vs 4.9%, p = 0.152; 3.1% vs 3.5%, p = 0.680 respectively). However, the rates of target vessel revascularization and major adverse coronary and cerebral event were significantly higher in PCI-treated patients than in those undergoing CABG (20% vs 1.2%, p <0.0001; 29% vs 15%, p = 0.034). Despite a much higher SS, patients who underwent PCI achieved comparable outcomes at 1 year to those with diabetes mellitus and a SS ≥ 33 as reported in the SYNTAX trial. In conclusion, in this single-center nonrandomized observational study, coronary revascularization by PCI is associated with increased major adverse coronary and cerebral events at 1-year follow-up, predominantly driven by a high rate of target vessel revascularization. Thus, CABG should remain the revascularization procedure of choice for diabetic patients with MVD and high SSs.

Percutaneous coronary intervention (PCI) versus coronary artery bypass grafting (CABG) in the treatment of diabetic patients with multi-vessel coronary disease: a meta-analysis

Diabetes is prevalent in patients with coronary artery disease. In diabetic patients with multi-vessel coronary disease, percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) are widely used for revascularization. We aimed to compare the effectiveness and safety of PCI and CABG in these patients. Nine randomized controlled trials were identified in which a total of 1047 diabetic patients were randomly assigned to PCI and 1054 to CABG. Results showed that five-year mortality was significantly higher in diabetic patients after PCI than after CABG (risk difference (RD) of 7%; P<0.001); repeated revascularization was more common after PCI than after CABG (one-year RD of 13%; P<0.001); major adverse cardiac and cerebrovascular events were also more frequent after PCI (one-year RD of 12%; P<0.001); however, the cerebrovascular accident rate was lower in the PCI group than the CABG group (one-year RD of -2%; P=0.004). Conclusively, in diabetic patients with multi-vessel coronary disease, CABG was not only more effective than PCI in reducing mortality but also led to fewer repeated revascularizations and fewer major adverse cardiac and cerebrovascular events. Despite these benefits, CABG did put diabetic patients at higher risk for cerebrovascular accident than PCI.

Influence of diabetes mellitus on long-term (five-year) outcomes of drug-eluting stents and coronary artery bypass grafting for multivessel coronary revascularization

Diabetes mellitus is a major risk factor for coronary artery disease (CAD) and for diffuse and progressive atherosclerosis. We evaluated the outcomes of drug-eluting stent (DES) placement and coronary artery bypass grafting (CABG) in 891 diabetic patients (489 for DES implantation and 402 for CABG) and 2,151 nondiabetic patients (1,058 for DES implantation and 1,093 for CABG) with multivessel CAD treated from January 2003 through December 2005 and followed up for a median 5.6 years. Outcomes of interest included death; the composite outcome of death, myocardial infarction (MI), or stroke; and repeat revascularization. In diabetic patients, after adjusting for baseline covariates, 5-year risk of death (hazard ratio 1.01, 95% confidence interval 0.77 to 1.33, p = 0.96) and the composite of death, MI, or stroke (hazard ratio 1.03, 95% confidence interval 0.80 to 1.31, p = 0.91) were similar in patients undergoing DES or CABG. However, rate of repeat revascularization was significantly higher in the DES group (hazard ratio 3.69, 95% confidence interval 2.64 to 5.17, p <0.001). These trends were consistent in nondiabetic patients (hazard ratio 0.80, 95% confidence interval 0.55 to 1.16, p = 0.23 for death; hazard ratio 0.77, 95% confidence interval 0.56 to 1.05, p = 0.10 for composite of death, MI, or stroke; hazard ratio 2.77, 95% CI 1.95 to 3.91, p <0.001 for repeat revascularization). There was no significant interaction between diabetic status and treatment strategy on clinical outcomes (p for interaction = 0.36 for death; 0.20 for the composite of death, MI, or stroke; and 0.40 for repeat revascularization). In conclusion, there was no significant prognostic influence of diabetes on long-term treatment with DES or CABG in patients with multivessel CAD.

Clinical review: Screening for coronary artery disease in type 2 diabetes

CLINICAL CONTEXT

Sensitive tools are available to diagnose occult ischemic and atherosclerotic coronary disease, yet screening for coronary artery disease (CAD) has not been shown to reduce cardiac events in patients with type 2 diabetes mellitus (T2DM). Professional guidelines are inconsistent regarding CAD screening recommendations, but it is suggested that those at highest risk (10-yr risk ≥20%) for cardiac events may benefit.

EVIDENCE ACQUISITION

We reviewed bibliographies of professional CAD screening guidelines, review articles, and clinical trials published within the last 10 yr, although we have included relevant older studies. We excluded studies that did not focus on T2DM or explicitly analyze that subgroup.

EVIDENCE SYNTHESIS

Although screening for coronary ischemia or atherosclerosis does provide incremental prognostic information in patients with T2DM and previously undiagnosed CAD, this has not been found to significantly impact outcomes. This appears to result from comparable efficacy of revascularization and optimal medical therapy in stable CAD. Limited evidence supports the hypothesis that those with more severe CAD (three-vessel, left main, proximal left anterior descending) amenable to bypass surgery may be potential beneficiaries of screening. However, the low prevalence of such candidates in the asymptomatic population, continuing advances with percutaneous intervention, and the lack of prospective trials makes such a recommendation currently unsupportable.

CONCLUSIONS

Findings to date do not support widespread screening for CAD in patients with T2DM. A future strategy identifying those at highest risk as screening candidates may ultimately be effective, but the optimal method for selecting those subjects or subsequent treatment is unknown.

Randomized trial of insulin versus usual care in reducing restenosis after coronary intervention in patients with diabetes. the STent Restenosis And Metabolism (STREAM) study

BACKGROUND

Diabetes status is an independent marker of restenosis after percutaneous coronary intervention (PCI). Previous studies suggest that metabolic abnormalities associated with diabetes increase stent restenosis by promoting intimal hyperplasia. Preclinical studies have indicated that insulin therapy reduces intimal hyperplasia. The objective of this study was to determine whether insulin-mediated glucose lowering reduces in-stent restenosis in patients with diabetes undergoing PCIs.

METHODS

We conducted a prospective, randomized, multicenter, open-labeled study with blinded outcomes. Patients were randomized 1:1 to daily bedtime subcutaneous NPH insulin (Novo Nordisk) versus usual therapy with oral hypoglycemic agents. The main outcomes were change in volume of intimal hyperplasia within the stent measured by intravascular ultrasound and late lumen loss by quantitative coronary angiography at 6 months post-PCI.

RESULTS

Seventy-eight patients (36 insulin, 42 usual care) were randomized. Eight patients in each group received drug-eluting stents. The insulin group achieved greater reductions in both glycosylated hemoglobin A1c (mean±S.D.) (insulin: 8.0%±1.2% to 6.7%±0.7% vs. control: 7.5%±1.2% to 7.1%±1.0 %, P=.0038) and fasting glucose (insulin: 9.3±3.8 to 5.8±1.7 vs. usual care: 8.4±2.4 to 7.7±2.0 mmol/l, P<.0001). There were no hypoglycemic events. At 6 months, there were no significant differences in either intravascular-ultrasound-determined neointimal volume (insulin: 41.2±38.9 vs. usual care: 48.4±40.2 mm(3), P=.33) or late lumen loss by angiography (insulin: 1.29±0.74 mm vs. usual care: 1.02±0.71 mm, P=.17).

CONCLUSIONS

Addition of a single bedtime dose of insulin in patients with diabetes does not influence in-stent restenosis.

Stent-related cardiac events beyond three years after implantation of the sirolimus-eluting stent (from the EVASTENT Patients)

The frequency of very late stent thrombosis (VLST) up to 3 years after sirolimus-eluting stent implantation is 0.5% to 0.6%/year but incertitude remains about the frequency of VLAST after 3 years. Diabetic (db+) and nondiabetic (db-) patients with or without multiple diseased vessels included in the EVASTENT matched-cohort registry were followed up to 6 years after stent implantation. Long-term follow-up was obtained for 1,564 of the 1,731 included patients. All-cause deaths (including cancer and complications of diabetes) occurred at steady rates of 2.5%/year up to 3 years and 1.2%/year after 3 years (difference not significant). In contrast, VLST (any Academic Research Consortium definition) was only 0.18%/year (95% confidence interval 0.08 to 0.39) after 3 years versus 0.63%/year (confidence interval 0.41 to 0.98) from 1 year to 3 years (p = 0.03). Target lesion revascularization rates were also lower after 3 years than before 3 years (1.9% vs 7%, p ≤ 0.01) with 66% of revascularization procedures after 3 years being for nontarget lesions. Six-year all-cause death and cardiac death cumulative rates were higher in db+ than in db- patients. However, after 3 years compared to before 3 years, no differences between db+ and db- patients were observed for target lesion revascularization and ST rates. It is noteworthy that 51% of patients continued to be on clopidogrel therapy nearly 6 years after receiving ≥ 1 sirolimus-eluting stent. In conclusion, all-cause deaths continued at a steady rate over 6 years. However, cardiac deaths and "very" VLST leveled out beyond 3 years.

The effect of diabetes on mortality in critically ill patients: a systematic review and meta-analysis

Introduction

Critically ill patients with diabetes are at increased risk for the development of complications, but the impact of diabetes on mortality is unclear. We conducted a systematic review and meta-analysis to determine the effect of diabetes on mortality in critically ill patients, making a distinction between different ICU types.

Methods

We performed an electronic search of MEDLINE and Embase for studies published from May 2005 to May 2010 that reported the mortality of adult ICU patients. Two reviewers independently screened the resultant 3,220 publications for information regarding ICU, in-hospital or 30-day mortality of patients with or without diabetes. The number of deaths among patients with or without diabetes and/or mortality risk associated with diabetes was extracted. When only crude survival data were provided, odds ratios (ORs) and standard errors were calculated. Data were synthesized using inverse variance with ORs as the effect measure. A random effects model was used because of anticipated heterogeneity.

Results

We included 141 studies comprising 12,489,574 patients, including 2,705,624 deaths (21.7%). Of these patients, at least 2,327,178 (18.6%) had diabetes. Overall, no association between the presence of diabetes and mortality risk was found. Analysis by ICU type revealed a significant disadvantage for patients with diabetes for all mortality definitions when admitted to the surgical ICU (ICU mortality: OR [95% confidence interval] 1.48 [1.04 to 2.11]; in-hospital mortality: 1.59 [1.28 to 1.97]; 30-day mortality: 1.62 [1.13 to 2.34]). In medical and mixed ICUs, no effect of diabetes on all outcomes was found. Sensitivity analysis showed that the disadvantage in the diabetic surgical population was attributable to cardiac surgery patients (1.77 [1.45 to 2.16], P < 0.00001) and not to general surgery patients (1.21 [0.96 to 1.53], P = 0.11).

Conclusions

Our meta-analysis shows that diabetes is not associated with increased mortality risk in any ICU population except cardiac surgery patients.

Myocardial function may improve equally in diabetic patients following both multivessel percutaneous coronary intervention and coronary artery bypass grafting: results from a CARDia trial substudy

AIMS

The CARDia (Coronary Artery Revascularization in Diabetes) trial compared coronary artery bypass grafting (CABG) and optimal percutaneous coronary intervention (PCI) in diabetic patients with multivessel coronary disease. Patients enrolled had symptoms of myocardial ischaemia. As symptom assessment is flawed in diabetic patients, a substudy was undertaken to compare the extent to which these revascularization strategies alter reversible ischaemia.

METHODS AND RESULTS

Seventy-one patients underwent stress echo at baseline and at 6 months. A 17-segment echocardiographic wall motion score index (WMSI) was assigned at baseline [WMSI(pre)] and at 6 months [WMSI(post)]. An overall score defined the difference: WMSI(∂) = WMSI(pre)--WMSI(post). Of 71 patients recruited, 42 underwent PCI and 29 CABG. Mean WMSI(pre) in the PCI group was 1.63 and mean WMSI(post) was 1.32. Mean WMSI(pre) in the CABG group was 1.69 and mean WMSI(post) was 1.46. The PCI WMSI(∂) was 0.31 and CABG WMSI(∂) was 0.23 (P = 0.8). Of 42 PCI patients, 39 demonstrated ischaemia at baseline. At 6 months 31 had improvements in ischaemia (79%), 5 showed no improvement, and 3 ischaemia worsened. Of 29 CABG patients, 23 demonstrated ischaemia at baseline. At 6 months, 20 had improvements in ischaemia (87%), 2 had no improvement, and in 1 ischaemia worsened. No difference was seen in the number of patients with improvements in reversible ischaemia between PCI and CABG [79 vs. 87%, (P = 0.9)].

CONCLUSION

Optimal revascularization in diabetic patients with multivessel disease remains controversial. This subset analysis of the CARDia trial suggests both PCI and CABG achieve similar improvement in reversible ischaemia.

Origin of restenosis after drug-eluting stent implantation in hyperglycemia is inflammatory cells and thrombus

AIMS

The cellular and molecular mechanisms and safety after drug-eluting stent (DES) implantation in diabetic patients are still poorly understood; therefore, in this study, we evaluated the pathologic responses of the sirolimus-eluting stent (SES) or paclitaxel-eluting stent (PES) in a type I diabetes mellitus (DM) rat model.

METHODS

The type I DM rat model was manipulated by intra-peritoneal streptozotocin injection. Two weeks later, DES was implanted in the aorta of rats with hyperglycemia or not as a control. Four weeks after DES implantation, the stented aorta was isolated and histomorphometric analysis was performed.

RESULTS

On histomorphometric analysis, increased thrombus, inflammatory cell infiltration, and neointimal hyperplasia (NIH) without change of the smooth muscle cell number after DES implantation were observed in DM rats compared with non-DM (NDM) rats. Furthermore, delayed coverage of mature endothelial cells defined as a von Willebrand factor expression and increased immature endothelial cells as a c-kit expression after DES implantation were observed in DM rats compared with NDM rats. Increased fibrin deposition and decreased hyaluronic acid accumulation at NIH after DES implantation were also observed in DM rats compared with NDM rats.

CONCLUSIONS

In conclusion, the main mechanism of restenosis after DES implantation under hyperglycemic conditions was initial thrombus with changes of the extracellular matrix rather than SMC proliferation. These results provided a therapeutic clue for the selection of DES and application of combination therapy using anti-thrombotic and anti-inflammatory drugs in diabetic patients.

Trends in postacute myocardial infarction management and mortality in patients with diabetes. A population-based study from 1995 to 2001

OBJECTIVE

To compare trends in coronary revascularization use and case fatality rate (CFR) following acute myocardial infarction in patients with and without diabetes.

METHODS

A retrospective study of 77,552 patients, 20 years of age or older (25% with diabetes), who were hospitalized for a first acute myocardial infarction in the province of Quebec between April 1995 and December 2001 was conducted. Administrative databases were used to identify patients and assess outcomes.

RESULTS

Compared with patients without diabetes, patients with diabetes underwent more coronary artery bypass graft (CABG) surgeries (11.1% versus 8.3%; P<0.0001) but fewer percutaneous coronary interventions (17.1% versus 20.2%; P<0.0001). The use of percutaneous coronary intervention increased substantially over time in both populations, driven mainly by an increase during the index admission (20.6% versus 16.6% per year; P=0.1144 in patients with and without diabetes, respectively). The use of CABG during the index admission increased markedly among patients with diabetes compared with those without (10.3% versus 5.3% per year; P=0.0072); however, at one-year following discharge, CABG use remained stable in patients with diabetes and fell in those without (-0.7% versus -5.3% per year; P=0.2046). Concomitantly, patients with diabetes presented a similar decline in CFR compared with patients without diabetes. The decline was more pronounced during the index admission (-5.0% versus -4.1% per year; P=0.282) than at one-year following discharge (-2.5% versus -2.5% per year; P=0.629) in patients with and without diabetes, respectively. However, fatal outcome remained higher in patients with diabetes than without, with an adjusted RR of 1.21 (95% CI 1.18 to 1.24) at one-year follow-up.

CONCLUSION

Overall, coronary revascularization use and CFR improved over time in patients with diabetes. Nevertheless, the mortality rate in patients with diabetes remains higher than in patients without diabetes, indicating that additional progress is required to improve the poorer prognosis in this population.

Three-vessel coronary disease in diabetics: personalized versus evidence-based revascularization strategy

A steady increase in the number of diabetic patients undergoing coronary revascularization has been recorded in recent years. The causes for this rise are found predominantly in the general demographic development of western industrialized nations, the epidemic progress and wide-spread of diabetes mellitus and changes in assignment behavior. In this article, the specific risk profile of diabetic coronary patients with three-vessel disease in percutaneous or surgical revascularization and tried and tested treatment concepts for this particularly challenging group of patients, with reference to the most recent study results will be presented. Particularly, the peculiarities of coronary heart disease in diabetic patients, the choice of revascularization method, different operative strategies for diabetic patients with coronary heart disease, and challenges faced during follow-up are discussed.

[Revascularization of coronary artery disease in diabetes mellitus]

Coronary artery disease in diabetes mellitus (DM) is still associated with a poor prognosis. Especially percutaneous coronary interventions (PCI) have a higher rate of complications and restenosis, so that surgical revascularization is usually favoured in DM. The development of drug-eluting stents has improved the results of PCI significantly, however, there are still not enough prospective data comparing them to bypass surgery. The present paper summarizes the current state of coronary revascularization.

Clinical outcomes in diabetic and non-diabetic patients with drug-eluting stents: results from the first phase of the prospective multicenter German DES.DE registry

BACKGROUND

Patients with diabetes mellitus (DM) undergoing coronary revascularization are at increased risk for adverse outcomes. Without sufficiently powered data from diabetic subgroup analyses and in absence of randomized controlled trials in diabetic patients with primary clinical outcomes controversy is ongoing over safety and efficacy of drug-eluting stents (DES) in diabetic patients.

METHODS AND RESULTS

Between October 2005 and October 2006, 1,659 diabetic and 3,559 non-diabetic patients treated with DES (Paclitaxel or Sirolimus-eluting stents) were enrolled at 98 Drug-Eluting-Stent.DEutschland (DES.DE) sites. Major adverse cardiac and cerebrovascular events (MACCE), defined as the composite of death, myocardial infarction, and stroke, as well as target vessel revascularization (TVR) were defined as primary endpoints. The baseline clinical and descriptive morphology of coronary artery disease revealed more severe findings in diabetic patients. At 1-year follow-up, diabetic patients treated with DES had significantly higher rates for overall death (5.6 vs. 3.4%; p < 0.01), myocardial infarction (4.8 vs. 3.4%; p = 0.05), stroke (1.7 vs. 0.9%; p < 0.05), MACCE (10.9 vs. 7.1%; p < 0.001), and overall stent thrombosis (4.9 vs. 3.3%; p < 0.01) with slightly elevated rates for TVR (12.0 vs. 10.4%; p = 0.17); data which remained after risk-adjustment.

CONCLUSION

Data collected in DES.DE revealed that despite the use of DES the risk of myocardial infarction, death, and thrombotic events remains higher in diabetic patients.

Randomized comparison of percutaneous coronary intervention with coronary artery bypass grafting in diabetic patients. 1-year results of the CARDia (Coronary Artery Revascularization in Diabetes) trial

OBJECTIVES

The purpose of this study was to compare the safety and efficacy of percutaneous coronary intervention (PCI) with stenting against coronary artery bypass grafting (CABG) in patients with diabetes and symptomatic multivessel coronary artery disease.

BACKGROUND

CABG is the established method of revascularization in patients with diabetes and multivessel coronary disease, but with advances in PCI, there is uncertainty whether CABG remains the preferred method of revascularization.

METHODS

The primary outcome was a composite of all-cause mortality, myocardial infarction (MI), and stroke, and the main secondary outcome included the addition of repeat revascularization to the primary outcome events. A total of 510 diabetic patients with multivessel or complex single-vessel coronary disease from 24 centers were randomized to PCI plus stenting (and routine abciximab) or CABG. The primary comparison used a noninferiority method with the upper boundary of the 95% confidence interval (CI) not to exceed 1.3 to declare PCI noninferior. Bare-metal stents were used initially, but a switch to Cypher (sirolimus drug-eluting) stents (Cordis, Johnson & Johnson, Bridgewater, New Jersey) was made when these became available.

RESULTS

At 1 year of follow-up, the composite rate of death, MI, and stroke was 10.5% in the CABG group and 13.0% in the PCI group (hazard ratio [HR]: 1.25, 95% CI: 0.75 to 2.09; p=0.39), all-cause mortality rates were 3.2% and 3.2%, and the rates of death, MI, stroke, or repeat revascularization were 11.3% and 19.3% (HR: 1.77, 95% CI: 1.11 to 2.82; p=0.02), respectively. When the patients who underwent CABG were compared with the subset of patients who received drug-eluting stents (69% of patients), the primary outcome rates were 12.4% and 11.6% (HR: 0.93, 95% CI: 0.51 to 1.71; p=0.82), respectively.

CONCLUSIONS

The CARDia (Coronary Artery Revascularization in Diabetes) trial is the first randomized trial of coronary revascularization in diabetic patients, but the 1-year results did not show that PCI is noninferior to CABG. However, the CARDia trial did show that multivessel PCI is feasible in patients with diabetes, but longer-term follow-up and data from other trials will be needed to provide a more precise comparison of the efficacy of these 2 revascularization strategies. (The Coronary Artery Revascularisation in Diabetes trial; ISRCTN19872154).

Revascularization for coronary artery disease in diabetes mellitus: angioplasty, stents and coronary artery bypass grafting

Patients with diabetes mellitus (DM) are prone to a diffuse and rapidly progressive form of atherosclerosis, which increases their likelihood of requiring revascularization. However, the unique pathophysiology of atherosclerosis in patients with DM modifies the response to arterial injury, with profound clinical consequences for patients undergoing percutaneous coronary intervention (PCI). Multiple studies have shown that DM is a strong risk factor for restenosis following successful balloon angioplasty or coronary stenting, with greater need for repeat revascularization and inferior clinical outcomes. Early data suggest that drug eluting stents reduce restenosis rates and the need for repeat revascularization irrespective of the diabetic state and with no significant reduction in hard clinical endpoints such as myocardial infarction and mortality. For many patients with 1- or 2-vessel coronary artery disease, there is little prognostic benefit from any intervention over optimal medical therapy. PCI with drug-eluting or bare metal stents is appropriate for patients who remain symptomatic with medical therapy. However, selection of the optimal myocardial revascularization strategy for patients with DM and multivessel coronary artery disease is crucial. Randomized trials comparing multivessel PCI with balloon angioplasty or bare metal stents to coronary artery bypass grafting (CABG) consistently demonstrated the superiority of CABG in patients with treated DM. In the setting of diabetes CABG had greater survival, fewer recurrent infarctions or need for re-intervention. Limited data suggests that CABG is superior to multivessel PCI even when drug-eluting stents are used. Several ongoing randomized trials are evaluating the long-term comparative efficacy of PCI with drug-eluting stents and CABG in patients with DM. Only further study will continue to unravel the mechanisms at play and optimal therapy in the face of the profoundly virulent atherosclerotic potential that accompanies diabetes mellitus.

Improved survival after coronary artery bypass grafting has not influenced the mortality disadvantage in patients with diabetes mellitus

OBJECTIVES

We sought to compare mortality after coronary artery bypass grafting in patients with and without diabetes mellitus undergoing operations during different time periods.

METHODS

We performed analyses of 12,415 primary isolated coronary artery bypass grafting operations performed during 1970-2003, with follow-up of 5-year mortality up to December 2006.

RESULTS

The prevalence of diabetes mellitus continuously increased up to 25% among patients undergoing coronary artery bypass grafting in 2003. The 1892 patients with type 2 diabetes mellitus were older, more often female, and more frequently had cardiovascular risk factors, acute coronary syndrome, 3-vessel disease, and severely reduced left ventricular function than patients without diabetes mellitus. Early mortality was 3.4% in patients with diabetes mellitus versus 1.8% in patients without diabetes mellitus. The multivariable adjusted odds ratio was 2.0, and the 95% confidence interval was 1.4 to 2.7. Early adjusted mortality was significantly lower in patients operated on during 2000-2003 than those operated on during 1970-1989 in patients with diabetes mellitus (odds ratio, 0.3; 95% confidence interval, 0.1-0.9) and without diabetes mellitus (odds ratio, 0.4; 95% confidence interval, 0.2-0.7). Mortality until 5 years was 14.6% in patients with diabetes mellitus versus 8.3% in patients without diabetes mellitus (hazard ratio, 1.8; 95% confidence interval, 1.5-2.0). Five-year mortality was reduced by 40% in patients operated on during 2000-2003 compared with that seen in those operated on during 1970-1989 in patients with and without diabetes mellitus.

CONCLUSIONS

Diabetes mellitus was associated with an almost 2-fold increased risk of early and 5-year mortality. Early and late mortality were substantially reduced in patients with and without diabetes mellitus operated on more recently, but the mortality disadvantage associated with diabetes mellitus was not eliminated.

Coating process and early stage adhesion evaluation of poly(2-hydroxy-ethyl-methacrylate) hydrogel coating of 316L steel surface for stent applications

In this study, a spray-coating method has been set up with the aim to control the coating of poly(2-hydroxy-ethyl-methacrylate) (pHEMA), an hydrophilic polymeric hydrogel, onto the complex surface of a 316L steel stent for percutaneous coronary intervention (PCI). By varying process parameters, tuneable thicknesses, from 5 to 20 microm, have been obtained with uniform and homogeneous surface without crack or bridges. Surface characteristics of pHEMA coating onto metal surface have been investigated through FTIR-ATR, contact angle measurement, SEM, EDS and AFM. Moreover, results from Single-Lap-Joint and Pull-Off adhesion tests as well as calorimetric analysis of glass transition temperature suggested that pHEMA deposition is firmly adhered on metallic surface. The pHEMA coating evaluation of roughness, wettability together with its morphological and chemical stability after three cycles of expansion-crimping along with preliminary results after 6 months demonstrates the suitability of the coating for surgical implantation of stent.

Five-year follow-up after sirolimus-eluting stent implantation results of the SIRIUS (Sirolimus-Eluting Stent in De-Novo Native Coronary Lesions) Trial

OBJECTIVES

The aim of this study was to examine the 5-year clinical safety and efficacy outcomes in patients enrolled in the SIRIUS (Sirolimus-Eluting Stent in De-Novo Native Coronary Lesions) trial.

BACKGROUND

The SIRIUS trial was a double-blinded randomized study that demonstrated that sirolimus-eluting stents (SES) significantly improved angiographic results (at 8 months) and clinical outcomes (at 9 and 12 months) compared with bare-metal stents (BMS).

METHODS

Patients (n = 1,058) with de novo native coronary artery lesions were randomized to either SES (n = 533) or control BMS (n = 525) and were followed for 5 years.

RESULTS

Between 1 and 5 years, additional clinical events were similarly distributed among the sirolimus and control groups. At 5 years, in sirolimus versus control patients, target lesion revascularization was 9.4% versus 24.2% (p < 0.001) and major adverse cardiovascular events and target vessel failure rates were 20.3% versus 33.5% and 22.5% versus 33.5%, respectively (p < 0.0001 for both). There were no significant differences in death, myocardial infarction, and nontarget lesion revascularization. No significant differences were observed in the cumulative incidence of stent thrombosis for sirolimus versus control patients with either protocol-derived (1.0% vs. 0.8%) or Academic Research Consortium definitions (3.9% vs. 4.2%).

CONCLUSIONS

In patients with noncomplex coronary artery disease, clinical outcomes 5 years after implantation of SES continue to demonstrate significant reduction in the need for repeat revascularization, with similar safety (death and myocardial infarction) compared with BMS, without evidence for either disproportionate late restenosis or late stent thrombosis.

Glycaemic control and restenosis after percutaneous coronary interventions in patients with diabetes mellitus: a report from the Insulin Diabetes Angioplasty study

OBJECTIVE

We investigated the impact of glucose control on target lesion restenosis after PCI in patients with type 2 diabetes.

METHODS

Ninety-three consecutive patients with type 2 diabetes accepted for PCI were randomised to intensified glucose control based on insulin (I-group; n=44) or to continue ongoing glucose-lowering treatment (C-group; n=49).The treatment target was a FBG of 5-7 mmol/L and HbA1c <6.5%. Information on target lesion restenosis after six months was available in 82 patients.

RESULTS

At baseline HbA1c and FBG did not differ between the I- and C-groups, respectively (HbA1c: 6.5 vs. 6.5%; p=1.0 and FBG: 7.0 vs. 7.3 mmol/L; p=0.3). After six months there was no significant change in HbA1c or FBG in either group (change in HbA1c: -0.2 vs.-0.1%; p=0.3 and in FBG: +0.2 vs. -0.3 mmol/L; p=0.3 in the I- and C-groups, respectively). Target lesion restenosis at six months did not differ, I vs. C = 41 and 44% (p=0.8). Independent predictors for restenosis were previous myocardial infarction (OR 8.0, 95% CI 2.5-25.7; p=<0.001) and FBG at baseline (OR for an increase by 1 mmol/L = 1.4, 95% CI 1.1-1.9; p=0.015).

CONCLUSIONS

Restenosis was predicted by baseline FBG suggesting that it would be of interest to target glucose normalisation in future trials. Intensified insulin treatment did not influence the rate of restenosis indicating that the main focus should be on lowering glucose rather than the tool to normalise glucose.

A randomized comparison of sirolimus-eluting versus bare metal stents in the treatment of diabetic patients with native coronary artery lesions: the DECODE study

OBJECTIVE

To compare the effects of sirolimus-eluting (SES) versus bare metal stents (BMS) on 6-month in-stent late luminal loss (LLL) and 1-year major adverse cardiac events (MACE) in diabetics undergoing percutaneous coronary interventions.

BACKGROUND

In studies of unselected patients, coronary restenosis rates have been lower with SES than with BMS. Comparisons of SES versus BMS in diabetics with more than one stenosis or more than one vessel disease are few.

METHODS

This open-label trial randomly assigned 200 diabetics with de novo coronary artery stenoses to receive up to three SES versus BMS in a 2:1 ratio. The patients underwent repeat coronary angiography at 6 months after the index procedure and were followed-up for 1 year. The primary study endpoint was in-stent LLL at 6 months.

RESULTS

Between August 2002 and May 2004, 83 patients (mean age = 60 years) with 128 lesions (mean = 1.5 per patient) were enrolled at four U.S. and seven Asian medical centers. Enrollment was terminated early by the Safety Monitoring Board because of a statistically significant difference in rates of clinical endpoints. The mean in-stent LLL at 6 months was 0.23 mm in SES versus 1.10 mm in BMS recipients (P < 0.001). At 12 months, 8 patients (15%) assigned to SES had experienced MACE versus 12 patients (41%) assigned to BMS (P = 0.006).

CONCLUSIONS

In diabetics, the mean 6-month in-stent LLL was significantly smaller, and 12-month MACE rate significantly lower, after myocardial revascularization with SES than with BMS.

Optimal revascularization strategy for diabetic patients with multivessel coronary artery disease: the duel between old hero and young warrior

Given the results of the BARI and ARTS I trials and a meta-analysis, coronary artery bypass surgery has been preferred to percutaneous coronary intervention in diabetics with multivessel coronary artery disease requiring hypoglycemic treatment and in whom internal mammary artery grafts can be used. This approach was strongly recommended in a 2002 ACC/AHA Task Force on the management of patients with acute coronary syndrome. But, these recommendations were made before the availability of drug-eluting stents. We strongly believe that the ongoing, multi-centre FREEDOM, CARDia and SYNTAX trials will elucidate the optimal revascularization strategy for diabetic patients with multivessel disease in the near future.

Barriers to generalizability of health economic evaluations in Latin America and the Caribbean region

Use and acceptance of health economic evaluations (HEEs) has been much greater in developed than in developing nations. Nevertheless, while developing countries lag behind in the development of HEE methods, they could benefit from the progress made in other countries and concentrate on ways in which existing methods can be used or would need to be modified to fulfill their specific needs. HEEs, as context-specific tools, are not easily generalizable from setting to setting. Existing studies regarding generalizability and transferability of HEEs have primarily been conducted in developed countries. Therefore, a legitimate question for policy makers in Latin America and the Caribbean region (LAC) is to what extent HEEs conducted in industrialized economies and in LAC are generalizable to LAC (trans-regional) and to other LAC countries (intra-regional), respectively. We conducted a systematic review, searching the NHS Economic Evaluation Database (NHS EED), Office of Health Economics Health Economic Evaluation Database (HEED), LILACS (Latin America health bibliographic database) and NEVALAT (Latin American Network on HEE) to identify HEEs published between 1980 and 2004. We included individual patient- and model-based HEEs (cost-effectiveness, cost-utility, cost-benefit and cost-consequences analyses) that involved at least one LAC country. Data were extracted by three independent reviewers using a checklist validated by regional and international experts. From 521 studies retrieved, 72 were full HEEs (39% randomized controlled trials [RCTs], 32% models, 17% non-randomized studies and 12% mixed trial-modeling approach). Over one-third of identified studies did not specifically report the type of HEE. Cost-effectiveness and cost-consequence analyses accounted for almost 80% of the studies. The three Latin American countries with the highest participation in HEE studies were Brazil, Argentina and Mexico. While we found relatively good standards of reporting the study's question, population, interventions, comparators and conclusions, the overall reporting was poor, and evidence of unfamiliarity with international guidelines was evident (i.e. absence of incremental analysis, of discounting long-term costs and effects). Analysis or description of place-to-place variability was infrequent. Of the 49 trial-based analyses, 43% were single centre, 33% multinational and 18% multicentre national. Main reporting problems included issues related to sample representativeness, data collection and data analysis. Of the 32 model-based studies (most commonly using epidemiological models), main problems included the inadequacy of search strategy, range selection for sensitivity analysis and theoretical justifications. There are a number of issues associated with the reporting and methodology used in multinational and local HEE studies relevant for LAC that preclude the assessment of their generalizability and potential transferability. Although the quality of reporting and methodology used in model-based HEEs was somewhat higher than those from trial-based HEEs, economic evaluation methodology was usually weak and less developed than the analysis of clinical data. Improving these aspects in LAC HEE studies is paramount to maximizing their potential benefits such as increasing the generalizability/transferability of their results.

Silent myocardial ischemia screening in patients with diabetes mellitus

The prevalence of diabetes mellitus is fairly increasing, especially in the developing countries. Diabetes is a major cardiovascular risk factor; it often leads to severe cardiovascular complications, and coronary artery disease (CAD) is the main cause of death in diabetic patients. Silent myocardial ischemia (SMI) is more frequent in diabetic patients. The progress made in detection and treatment of CAD allows reconsidering the screening of SMI, in the hope that early CAD diagnosis leads to a more effective therapy and the decrease of cardiovascular complications and mortality. However, the benefit of systematic SMI screening remains discussed. Current guidelines recommend screening SMI in asymptomatic diabetic patients selected for high cardiovascular risk (i.e. with two or more other cardiovascular risk factors, or peripheral or carotid arterial disease, or proteinuria). ECG stress test can be recommended in first intention if maximal heart rate can be achieved. For patient with inconclusive ECG stress test, myocardial scintigraphy seems more accurate than stress echocardiography. Coronary angiogram should be performed in case of positive stress test. Further evaluations of systematic screening have to be conducted on broad randomized trial.

Multivessel disease: percutaneous coronary intervention for classic coronary artery bypass grafting indications

Multivessel coronary artery disease is characterized by involvement of greater than 1 epicardial coronary artery or the unprotected left main. The choice of revascularization strategy in this setting remains a critical issue in cardiology. Although coronary artery bypass grafting has traditionally been the revascularization strategy for most patients with multivessel disease, there has been a gradual shift toward percutaneous revascularization. Early randomized clinical trials showed coronary artery bypass grafting to be superior to medical therapy. However, trials comparing coronary artery bypass grafting to bare metal stenting have not shown a mortality benefit. Advancements in interventional techniques will continue to challenge the notion that coronary artery bypass grafting is the standard therapy for patients with multivessel coronary disease. Several ongoing randomized clinical trials comparing coronary artery bypass grafting to drug-eluting stents will provide valuable insight into the role of each procedure. In this article, we review the existing literature and discuss future directions in the management of the patient with multivessel disease.

Comparison of effectiveness and safety of sirolimus-eluting stents versus bare-metal stents in patients with diabetes mellitus (from the Italian Multicenter Randomized DESSERT Study)

Few studies directly compared drug-eluting stents and bare-metal stents (BMSs) in diabetic patients. DESSERT was an Italian multicenter randomized trial to show the efficacy of sirolimus-eluting stents (SESs) compared with BMSs in de novo lesions of diabetic patients treated with insulin and/or oral antidiabetics for > or =3 months on top of glycoprotein IIb/IIIa inhibitors. The primary end point was in-stent late lumen loss, assessed using centralized quantitative coronary angiography at 8-month follow-up. Centrally adjudicated composite major adverse cardiac events (MACEs) and target-vessel failure (TVF; death, treated vessel-related acute myocardial infarction, and target-vessel revascularization) at 30 days and 9 and 12 months were secondary end points. Seventy-five patients were randomly assigned to an SES (109 lesions), and 75 (109 lesions), to a BMS. The 2 groups were well balanced for clinical, anatomic, and procedural characteristics. In-stent late lumen loss decreased from 0.96 +/- 0.61 mm for BMSs to 0.14 +/- 0.33 for SESs (p <0.001), and in-segment binary restenosis was 38.8% versus 3.6%, respectively (p <0.001). Twelve-month clinical events were significantly lower in the sirolimus group: MACEs 22.1% versus 40% (p = 0.023), target-lesion revascularization 5.9% versus 30% (p <0.001), and TVF 14.7% versus 34.3% (p = 0.008). At multivariate analysis, stent type was confirmed as an independent predictor of in-segment late loss (p <0.001), binary restenosis (p <0.001), 12-month TVF (p = 0.010), and 12-month MACEs (p = 0.037). In conclusion, the randomized DESSERT showed SESs to be safe and effective in decreasing both angiographic parameters of restenosis and incidence of MACEs compared with BMSs in diabetic patients with de novo 1- or 2-vessel coronary stenoses.