Impact of diabetes on the benefits from everolimus-eluting stent as compared to first-generation drug-eluting stent in patients with ST elevation myocardial infarction

Glycaemic control in people with diabetes following acute myocardial infarction

Diabetes is a highly prevalent disease associated with considerable cardiovascular end organ damage and mortality. Despite significant changes to the management of acute myocardial infarction over the last two decades, people with diabetes remain at risk of complications and mortality following a myocardial infarct for a multitude of reasons, including increased coronary atherosclerosis, associated coronary microvascular dysfunction, and diabetic cardiomyopathy. Dysglycaemia causes significant endothelial dysfunction and upregulation of inflammation within the vasculature and epigenetic changes mean that these deleterious effects may persist despite subsequent efforts to tighten glycaemic control. Whilst clinical guidelines advocate for the avoidance of both hyper- and hypoglcyaemia in the peri-infarct period, the evidence base is lacking, and currently there is no consensus on the benefits of glycaemic control beyond this period. Glycaemic variability contributes to the glycaemic milieu and may have prognostic importance following myocardial infarct. The use of continuous glucose monitoring means that glucose trends and parameters can now be captured and interrogated, and its use, along with newer medicines, may provide novel opportunities for intervention after myocardial infarction in people with diabetes.

Diabetes and restenosis

Restenosis, defined as the re-narrowing of an arterial lumen after revascularization, represents an increasingly important issue in clinical practice. Indeed, as the number of stent placements has risen to an estimate that exceeds 3 million annually worldwide, revascularization procedures have become much more common. Several investigators have demonstrated that vessels in patients with diabetes mellitus have an increased risk restenosis. Here we present a systematic overview of the effects of diabetes on in-stent restenosis. Current classification and updated epidemiology of restenosis are discussed, alongside the main mechanisms underlying the pathophysiology of this event. Then, we summarize the clinical presentation of restenosis, emphasizing the importance of glycemic control in diabetic patients. Indeed, in diabetic patients who underwent revascularization procedures a proper glycemic control remains imperative.

Benefits with drug-coated balloon as compared to a conventional revascularization strategy for the treatment of coronary and non-coronary arterial disease: a comprehensive meta-analysis of 45 randomized trials

BACKGROUND

Drug-coated balloons (DCB) have shown promising results for the percutaneous treatment of de novo and restenotic lesions, involving both the coronary and femoropopliteal district. However, clinical outcomes data associated with the use of this devices are still unclear, with potential warnings on increased mortality being raised from initial studies. We aimed at performing an updated and comprehensive meta-analysis comparing DCB with conventional percutaneous revascularization strategies for the treatment of coronary (CAD) or peripheral artery disease (PAD).

METHODS

Literature and main scientific session abstracts were searched for studies comparing DCB vs a standard percutaneous revascularization strategy, with or without stenting, for the treatment of CAD and PAD. The primary efficacy endpoint was mortality. Secondary endpoints were recurrent acute ischemic events (myocardial infarction or amputation) or target lesion revascularization (TLR).

RESULTS

We included 45 randomized trials, (CAD: 27 studies, PAD: 18 studies) with an overall population of 7718 patients, (56.4%) randomized to a DCB strategy. At a mean follow-up of19.3 ± 15.2 months, death occurred in 5.8% of the patients, with no significant difference between DCB or conventionally treated patients (5.9% vs 5.7%, OR[95%CI] = 0.89[0.71,1.11], p = 0.31; phet = 0.43). We observed a non-significant reduction in recurrent acute ischemic events, whereas the use of DCB significantly reduced the rate of TLR, with larger benefits observed in patients with PAD and respect to balloon-only angioplasty, while being lower in comparison with stent implantation. No significant interaction was observed with de novo lesions or in-stent restenosis.

CONCLUSIONS

Based on the current meta-analysis, the use of drug-coated balloons for the percutaneous treatment of CAD and PAD is associated to a comparable risk of mortality and recurrent acute ischemic events as compared to a conventional revascularization strategy, although offering larger benefits in terms of TLR, especially when compared with balloon-only angioplasty and in femoropopliteal disease.

Comparison of First- and Second-Generation Drug-Eluting Stents in Patients with ST-Segment Elevation Myocardial Infarction Based on Pre-Percutaneous Coronary Intervention Thrombolysis in Myocardial Infarction Flow Grade

This study aims to investigate the two-year clinical outcomes between first-generation (1G) and second-generation (2G) drug-eluting stents (DES) based on pre-percutaneous coronary intervention (PCI) thrombolysis in myocardial infarction (TIMI) flow grade (pre-TIMI) in patients with ST-segment elevation myocardial infarction (STEMI). Overall, 17,891 STEMI patients were classified into two groups: pre-TIMI 0/1 group (n = 12,862; 1G-DES (n = 4318), 2G-DES (n = 8544)) and pre-TIMI 2/3 group (n = 5029; 1G-DES (n = 2046), 2G-DES (n = 2983)). During a two-year follow-up period, major adverse cardiac events (MACEs) defined as all-cause death, recurrent myocardial infarction (re-MI), or any repeat revascularization and stent thrombosis (ST) were considered as the primary and the secondary outcomes. In the pre-TIMI 0/1 and 2/3 groups, the cumulative incidences of MACEs (adjusted hazard ratio (aHR): 1.348, p < 0.001, and aHR: 1.415, p = 0.02, respectively) and any repeat revascularization (aHR: 1.938, p < 0.001, and aHR: 1.674, p = 0.001, respectively) were significantly higher in the 1G-DES than in the 2G-DES. However, sirolimus-eluting stent showed similar cumulative incidence of any repeat revascularization compared with zotarolimus-eluting stent and biolimus-eluting stent in both pre-TIMI 0/1 and 2/3 groups. The cumulative incidences of all-cause death, re-MI, and ST were similar between the 1G-DES and 2G-DES groups. In this study, 2G-DES showed better clinical outcomes than 1G-DES concerning MACEs and any repeat revascularization regardless of pre-TIMI. However, more research is needed to support these results.

Poly (l-lactic acid) bioresorbable scaffolds versus metallic drug-eluting stents for the treatment of coronary artery disease: A meta-analysis of 11 randomized trials

BACKGROUND

Bioresorbable vascular scaffolds (BVS) have been proposed for overcoming the long-term limitations of permanent metallic stents, while theoretically warranting similar advantages in plaque stabilization and anti-restenotic drug delivery in the early postrevascularization phase. However, increased rates of malapposition, restenosis, or thrombosis have emerged from initial trials with BVS, that were nevertheless underpowered for the evaluation of the real outcome benefits of these coronary devices. The recent completion of newer randomized clinical trials paves the way to the present meta-analysis, aiming at the comparison of Poly (l-Lactic acid) BVS (PLLA-BVS) versus metallic drug-eluting stents (DES) in the treatment of coronary stenoses.

METHODS

Literature and main scientific session abstracts were searched for randomized clinical trials (RCTs) comparing drug-eluting BVS versus metallic DES for the treatment of coronary artery disease (CAD). The primary efficacy endpoint was mortality, secondary endpoints were cardiovascular death, myocardial infarction, target lesion revascularization (TLR), stent thrombosis and the composite of device-oriented target lesion failure (TLF).

RESULTS

We included 11 randomized trials, for a total population of 10,707 patients, 54.5% treated with BVS. The major indication for PCI was stable CAD, whereas acute coronary syndrome represented 30% of the patients. At a mean follow-up of 2.64 years (1-5 years), mortality occurred in 2.71% of the patients, with no difference according to the type of implanted stent (OR[95%CI] = 0.94 [0.74, 1.20], p = .62). No interaction was observed according to patients' risk profile or the rate of diabetes and ACS. However, a significant increase in myocardial infarction, stent thrombosis, TLR and TLF was observed with BVS as compared to DES.

CONCLUSIONS

The present meta-analysis provides the most updated data on the use of PLLA-BVS for the treatment of CAD. We documented a poorer performance of these new coronary devices, as compared to new generation metallic DES, being associated with an increased rate of recurrent cardiovascular events. However, such ischemic complications did not impact on mortality, with a comparable survival independently from the type of stent.

Thymosin β4-mediated protective effects in the heart

INTRODUCTION

Despite recent advances in the treatment of coronary heart disease, a significant number of patients progressively develop heart failure. Reduction of infarct size after acute myocardial infarction and normalization of microvasculature in chronic myocardial ischemia could enhance cardiac survival.

AREAS COVERED

Induction of neovascularization using vascular growth factors has emerged as a promising novel approach for cardiac regeneration. Thymosin β4 (Tβ4) might be a promising candidate for the treatment of ischemic heart disease. It has been characterized as a major G-actin-sequestering factor regulating cell motility, migration, and differentiation. During cardiac development, Thymosin β4 seems essential for vascularization of the myocardium. In the adult organism, Thymosin β4 has anti-inflammatory properties, increases myocyte and endothelial cell survival accompanied by differentiation of epicardial progenitor cells. In chronic myocardial ischemia, Tβ4 overexpression enhances micro- and macrovasculature in the ischemic area and thereby improves myocardial function. A comparable effect is seen in diabetic and dyslipidemic pig ischemic hearts, suggesting an attractive therapeutic potential of adeno-associated virus encoding for Tβ4 for patients with ischemic heart disease.

EXPERT OPINION

Induction of mature micro-vessels is a prerequisite for chronic myocardial ischemia and might be achieved via a long-term overexpression of Thymosin β4.

Impact of Long-Term Dual Antiplatelet Therapy on Immature Platelet Count and Platelet Reactivity

The immature platelet count (IPC) is a potential marker of platelet reactivity. We assessed the relationship between IPC during chronic dual antiplatelet therapy (DAPT) and the response to antiplatelet drugs (acetylsalycilic acid + clopidogrel/ticagrelor). We included 286 patients: 167 (58.4%) patients received ticagrelor and 119 (41.6%) received clopidogrel. At a median follow-up of 46.5 days, the variation in IPC displayed an absolute median (interquartile range [IQR]) of −11.9 × 103/µL (−182.7 to 160.8), corresponding to a median percentage change in IPC ([%ΔIPC] IQR) of −0.3% (−21.9% to 35.5%), with an increase in IPC levels in those on ticagrelor and a decrease in IPC levels in those on clopidogrel. We observed an inverse association of lower platelet reactivity at different tests and a higher increase in IPC ( r = −0.14, P = .04 for arachidonic acid test; r = −0.12, P = .05 for collagen test; and r = −0.13, P = .02 for adenosine diphosphate test [ADP]). The rate of poor effectiveness of ADP antagonists was the only independent predictor of a ΔIPC above the third tertile (odds ratio [95% confidence interval] = 0.55 [0.32-0.99]; P = .048). We showed that in patients treated with chronic DAPT, an increase in IPC is significantly related to lower levels of platelet reactivity.

Circulating Prolidase Activity in Patients with Myocardial Infarction

Background

Collagen is a major determinant of atherosclerotic plaque stability. Thus, identification of differences in enzymes that regulate collagen integrity could be useful for predicting susceptibility to atherothrombosis or for diagnosing plaque rupture. In this study, we sought to determine whether prolidase, the rate-limiting enzyme of collagen turnover, differs in human subjects with acute myocardial infarction (MI) versus those with stable coronary artery disease (CAD).

Methods

We measured serum prolidase activity in 15 patients with stable CAD and 49 patients with acute MI, of which a subset had clearly defined thrombotic MI (n = 22) or non-thrombotic MI (n = 12). Prolidase activity was compared across study time points (at cardiac catheterization, T0; 6 h after presentation, T6; and at a quiescent follow-up, Tf/u) in acute MI and stable CAD subjects. We performed subgroup analyses to evaluate prolidase activity in subjects presenting with acute thrombotic versus non-thrombotic MI.

Results

Although prolidase activity was lower at T0 and T6 versus the quiescent phase in acute MI and stable CAD subjects (p < 0.0001), it was not significantly different between acute MI and stable CAD subjects at any time point (T0, T6, and Tf/u) or between thrombotic and non-thrombotic MI groups. Preliminary data from stratified analyses of a small number of diabetic subjects (n = 8) suggested lower prolidase activity in diabetic acute MI subjects compared with non-diabetic acute MI subjects (p = 0.02).

Conclusion

Circulating prolidase is not significantly different between patients with acute MI and stable CAD or between patients with thrombotic and non-thrombotic MI. Further studies are required to determine if diabetes significantly affects prolidase activity and how this might relate to the risk of MI.