Impact of temporary traffic bans on the risk of acute coronary syndromes in a large metropolitan area

BACKGROUND

Strong epidemiologic evidence has highlighted the role of pollution, on top of adverse climate features, as a novel cardiovascular risk factor. However, mechanistic proof that reducing pollution may be beneficial to prevent atherothrombotic events is limited. We aimed at appraising the impact of temporary traffic bans in a large metropolitan area on the risk of acute coronary syndromes.

METHODS

Aggregate and anonymized data from 15 tertiary cardiac care centers were obtained detailing precoronavirus disease 2019 (COVID-19) daily cases of ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI), including those treated with percutaneous coronary intervention (PCI). Data on pollutants and climate were sought for the same days. Mixed level regression was used to compare the week before vs after the traffic ban (Fortnight analysis), the 3 days before vs. after (Weekly analysis) and the Sunday before vs. after (Sunday analysis).

RESULTS

A total of 8 days of temporary traffic bans were included, occurring between 2017 and 2020, totaling 802 STEMI and 1196 NSTEMI in the Fortnight analysis, 382 STEMI and 585 in the Weekly analysis, and 148 STEMI and 210 NSTEMI in the Sunday analysis.Fortnight and Sunday analyses did not disclose a significant impact of traffic ban on STEMI or NSTEMI (all P>0.05). Conversely, Weekly analysis showed non-significant changes for STEMI, but a significant decrease in daily NSTEMI when comparing the 3 days before the traffic ban with the ban day (P=0.043), as well as the 3 days before vs. the 3 days after the ban (P=0.025). No statistically significant effect of traffic ban was found at Fortnight, Weekly or Sunday analyses for daily mean concentrations of benzene, carbon monoxide, nitric oxide, nitrogen dioxide, ozone, sulfur dioxide, particulate matter (PM) <2.5 µm or PM <10 µm (all P>0.05). However, minimum daily concentrations showed a significant reduction of ozone during the ban in comparison to the week preceding it (P=0.034), nitric oxide during the ban in comparison to the 3 days preceding it (P=0.046), and an increase in benzene during the ban in comparison to the Sunday before (P=0.039).

CONCLUSIONS

Temporary traffic ban may favorably reduce coronary atherothrombotic events, and in particular NSTEMI, even if not globally and immediately impacting on environmental pollution. Further controlled studies are required to confirm and expand this hypothesis-generating results.

Nanotechnology in diagnosis and treatment of coronary artery disease

Nanotechnology could provide a new complementary approach to treat coronary artery disease (CAD) which is now one of the biggest killers in the Western world. The course of events, which leads to atherosclerosis and CAD, involves many biological factors and cellular disease processes which may be mitigated by therapeutic methods enhanced by nanotechnology. Nanoparticles can provide a variety of delivery systems for cargoes such as drugs and genes that can address many problems within the arteries. In order to improve the performance of current stents, nanotechnology provides different nanomaterial coatings, in addition to controlled-release nanocarriers, to prevent in-stent restenosis. Nanotechnology can increase the efficiency of drugs, improve local and systematic delivery to atherosclerotic plaques and reduce the inflammatory or angiogenic response after intravascular intervention. Nanocarriers have potential for delivery of imaging and diagnostic agents to precisely targeted destinations. This review paper will cover the current applications and future outlook of nanotechnology, as well as the main diagnostic methods, in the treatment of CAD.

Prednisolone- and sirolimus-eluting stent: Anti-inflammatory approach for inhibiting in-stent restenosis

Glucocorticoids are powerful anti-inflammatory, immunosuppressive, and anti-proliferative agents. The aim of this study was to evaluate the effectiveness of a prednisolone- (PDScs) and sirolimus-coated stent (SRLcs) in preventing artery vessel neointimal hyperplasia and inflammatory reactions in vitro and in vivo. PDS, a synthetic glucocorticoid, is a derivative of cortisol, which is used to treat a variety of inflammatory and autoimmune conditions. The stents were fabricated with PDS, SRL, or both agents using a layer-by-layer coating system (designated as PDScs, SRLcs, and PDSRLcs, respectively). The surface morphology of the PDScs showed an evenly dispersed and roughened shape, which was smoothened by the SRL coating. Half of the total drug amounts were released within seven days, followed by an additional release, which continued for up to 28 days. The proliferation of smooth muscle cells was inhibited in the SRLcs group (31.5 ± 4.08%), and this effect was enhanced by PDS addition (PDSRLcs, 46.8 ± 8.11%). Consistently, in the animal study, the restenosis rate was inhibited by the SRLcs and PDSRLcs (18.5 ± 6.23% and 14.5 ± 3.55%, respectively). Especially, fibrin expression and inflammation were suppressed in the PDS-containing group (PDScs, 0.6 ± 0.12 and 1.4 ± 0.33; PDSRLcs, 0.7 ± 0.48 and 1.7 ± 0.12, respectively) compared to PDS non-containing groups (BMS, 1.1 ± 0.12, and 1.8 ± 0.55; SRLcs, 1.6 ± 0.32 and 2.0 ± 0.62, respectively). Moreover, re-endothelialization was enhanced in the PDScs group as determined using immunohistochemistry with a cluster of differentiation (CD)-31 antibodies. These results suggest that the inhibitory effect of SRLcs on anti-restenosis can be accelerated by additional coating with PDS, which has promising properties as a bioactive compound with useful anti-inflammatory effects.

Targeted anti-inflammatory systemic therapy for restenosis: the Biorest Liposomal Alendronate with Stenting sTudy (BLAST)-a double blind, randomized clinical trial

BACKGROUND

Activation of systemic innate immunity is critical in the chain of events leading to restenosis. LABR-312 is a novel compound that transiently modulates circulating monocytes, reducing accumulation of these cells at vascular injury sites and around stent struts. The purpose of the study was to examine the safety and efficacy of a single intravenous bolus of LABR-312 in reducing restenosis in patients treated for coronary narrowing. Patient response was examined in light of differential inflammatory states as evidenced by baseline circulating monocyte levels, diabetes mellitus, and acute coronary syndrome.

METHODS

BLAST is a Phase II prospective, randomized, multicenter, double-blind, placebo-controlled trial that assessed the safety and efficacy of LABR-312. Patients were randomized to receive LABR-312 at 2 dose levels or placebo as an intravenous infusion during percutaneous coronary intervention and bare metal stent implantation. The primary end point was mean angiographic in-stent late loss at 6 months.

RESULTS

Patients (N = 225) were enrolled at 12 centers. There were no safety concerns associated with the study drug. For the overall cohort, there were no differences between the groups in the primary efficacy end point (in-stent late loss of 0.86 ± 0.60 mm, 0.83 ± 0.57 mm, and 0.81 ± 0.68 mm for the placebo, low-dose, and high-dose group, respectively; P = not significant for all comparisons). In the prespecified subgroups of patients with a baseline proinflammatory state, patients with diabetes mellitus, and patients with high baseline monocyte count, there was a significant treatment effect.

CONCLUSIONS

Intravenous administration of LABR-312 to patients undergoing percutaneous coronary intervention is safe and effectively modulates monocyte behavior. The average late loss did not differ between the treatment and placebo groups. However, in the inflammatory patient group with baseline monocyte count higher than the median value, there was a significant reduction in late loss with LABR-312.

Randomized comparison of cost-saving and effectiveness of oral rapamycin plus bare-metal stents with drug-eluting stents: three-year outcome from the randomized oral rapamycin in Argentina (ORAR) III trial

OBJECTIVES

The Oral Rapamycin in ARgentina (ORAR) III trial is a randomized study comparing a strategy of oral rapamycin (OR) plus bare-metal stent (BMS) versus a strategy of drug-eluting stents (DES) in patients with de novo coronary lesions. The purpose of this study was to assess the 3 years cost-effectiveness outcome of each strategy.

BACKGROUND

OR after BMS has been associated with reduction of target vessel revascularization (TVR) although its value in long-term efficacy in comparison with DES is unknown.

METHODS

In three hospitals in Buenos Aires, Argentina, 200 patients were randomized to OR plus BMS (n = 100) or DES (n = 100). Primary objectives were costs and effectiveness. Cost analysis included in-hospital and follow-up costs. Safety was defined as the composite of death, myocardial infarction (MI), and stroke. Efficacy was defined as TVR.

RESULTS

Baseline characteristics between groups were similar. The 3-year follow-up rate was 99%. Cardiac mortality was 2% and 5% in OR group and DES group, respectively (P = 0.44). The composite of death, MI and stroke rate was 11% in OR group and 20% in DES group (P = 0.078). TVR rate was 14.5% in OR group and 17.6% in DES group (P = 0.50), respectively. Three year cumulative costs were significantly lower in the OR arm as compared to the DES arm (P = 0.0001) and DES strategy did not result cost-effective according to the non-inferiority test.

CONCLUSIONS

At 3 years follow-up, there were no differences in effectiveness between the two strategies, and DES strategy was not more cost-effective as compared to OR plus BMS.

Immunosuppressive therapy with oral prednisone to prevent restenosis after PCI. A multicenter randomized trial

BACKGROUND

Prednisone at immunosuppressive doses after stenting has shown remarkable efficacy in reducing ischemic recurrences in nondiabetic patients with high post-procedural levels of C-reactive protein; the study aim was to compare the clinical outcome obtained in a control group of patients treated with bare metal stents versus 2 other study groups--bare metal stent plus oral prednisone or drug eluting stents--assuming similar optimal adjunctive medical treatment.

METHODS

Five tertiary Italian hospitals enrolled 375 nondiabetic patients with coronary artery disease and no contraindications to dual antiplatelet treatment or corticosteroid therapy in a randomized, controlled study performed between 2007 and 2009. Patients were allocated into 3 study groups: bare metal stents (controls), bare metal stents followed by a 40-day prednisone treatment, or drug-eluting stents. The primary endpoint was the event-free survival of cardiovascular death, myocardial infarction, and recurrence of ischemia needing repeated target vessel revascularization at 1 year as adjudicated by an independent clinical events committee.

RESULTS

One-year follow-up was obtained in all patients. Patients receiving bare metal stents alone as compared to those treated with prednisone or drug-eluting stents had lower event-free survival; the primary endpoint was 80.8% in controls compared to 88.0% in the prednisone and 88.8% in the drug-eluting stent groups, respectively (P=.04 and .006).

CONCLUSION

Compared with bare metal stents alone, prednisone treatment after bare metal stents or drug-eluting stent implantation result in a better event-free survival at 1 year.

Emerging drugs for coronary restenosis: the role of systemic oral agents the in stent era

Introduction of drug eluting stents (DES) during percutaneous coronary interventions significantly reduces the rate of angiographic restenosis, target lesion and vessel revascularization. In spite of these benefits, other clinical hard end points such as death or myocardial infarction were not reduced and, furthermore, new concerns associated with the presence of late and very late stent thrombosis have been raised. The requirement of long-term dual antiplatelet therapy is another limitation associated with DES. Conversely, in this decade, other options to DES have been simultaneously discussed in observational and randomized studies. Several registries and randomized trials using the systemic approach with anti-inflammatory, immunosuppressive or antiplatelet therapies have been identified and discussed in this manuscript. In spite of all randomized studies with oral therapies in the bare metal stent (BMS) era demonstrating positive reductions in coronary restenosis, this practice has not been introduced clinically. Furthermore, a recent randomized trial comparing oral sirolimus plus BMS versus DES demonstrated that the first approach was cost saving and of comparable efficacy to DES. Conclusive evidence of high incidence of late and very late stent thrombosis with DES, together with clinical limitations for its widespread use, has opened up a large opportunity to search for alternative therapies in coronary restenosis prevention.