Pre-hospital thrombolysis.

Coronary heart disease (CHD) is a major cause of mortality in India. Patients in India, who have acute coronary syndromes, have a higher rate of STEMI than do patients in developed countries. Since most of these patients are poor, they are less likely to get evidence-based treatments, and have a greater 30-day mortality. Reduction of delays in access to hospital and provision of affordable treatments could reduce this. Treatment regimes for AMI should aim to open the artery as soon as possible and as wide as possible. In patients suitable for thrombolytic treatment, time is critical and reperfusion should be initiated as soon as possible. Some adjunctive therapies are also beneficial, in particular, the antiplatelet agent aspirin, which should be given in the prehospital setting when a diagnosis of AMI is suspected. Despite availability of good treatment, mortality from AMI is showing no further reduction due to the prehospital phase and in-hospital delays. Thrombolysis is almost always delivered to patients after arriving in hospital, losing valuable time (and hence heart muscle). Newer drugs combined with recognition of improved outcomes have prompted attempts to decrease the time from symptom onset to treatment delivery via Pre Hospital Thrombolysis (PHT). However, PHT is significantly superior to in-hospital thrombolysis (IHT). This is especially important in regions where PCI is not available. In the RIKS-HIA and NRMI, PHT had better outcomes than IHT, but patients who received PPCI had lower mortality and re-infarction rates. They concluded that within 2 h of symptom onset, patients should receive PHT only if PPCI is not available within 4 h. In CAPTIM, which compared PPCI and PHT followed by PCI if thrombolysis failed and in GRACIA-1 trial, which tested the role of systematic PCI within 24 h of thrombolysis, the policy of systematic PCI following thrombolysis yielded better results than conservative management. The American Heart Association (AHA) and the American College of Cardiology (ACC) favour the use of PHT over PCI, placing the emphasis on the time factor rather than on the method of reperfusion. However, if PHT cannot be administered, the patient should be treated with PPCI within 90 min of first medical contact or therapy within 30 min such that the total ischaemic time is 120 min. The National Institute for Clinical Excellence supports reperfusion with fibrinolytics, recommending PHT using the newer agents, reteplase and tenecteplase, whose bolus application simplifies administration. PHT constitutes one of the means to shorten delays before the administration of reperfusion therapy. However, it poses several organizational problems that can find different answers according to each regional/national system of care. A number of barriers exist that limit the actual use of PHT. Thus the system of care chosen is likely to have a definite impact on the percentage of STEMI patients in whom PHT can be delivered.

In vitro and in vivo performance of a dual drug-eluting stent (DDES).

This study reports on a dual drug-eluting stent (DDES) that has an anti-proliferative and an anti-thrombotic in a biodegradable polymer-coated onto a cobalt-chromium stent. The DDES was prepared by spray coating the bare metal stent with a biodegradable polymer loaded with sirolimus and triflusal, to treat against restenosis and thrombosis, respectively. The 2-layered dual-drug coated stent was characterized in vitro for surface properties before and after expansion, as well as for possible delamination by cross-sectioning the stent in vitro. The in vitro anti-platelet behavior of the triflusal-loaded films was investigated by using dynamic platelet adhesion measurements. Additionally, the in vitro degradation and release study of the films and the stents w/single sirolimus and dual sirolimus-triflusal in different formulations were examined. Finally, in vivo studies (in a porcine carotid artery model) were performed for acute thrombosis, inflammation and restenosis at 30 days. The in vitro results show DDES can sustain release both anti-proliferation drug (sirolimus) and anti-thrombosis drug (triflusal), two drugs were controlled in different rates to effectively reduce thrombosis and proliferation at the same time. In vivo results show a significant reduction in restenosis with dual-drug eluting stent compared with the controls (a bare metal stent, a sirolimus coated and a pure polymer-coated stent). The reduction in restenosis with a dual sirolimus-triflusal eluting stent is associated with an inhibition of inflammation, especially thrombus formation, suggesting that such dual-drug eluting stents have a role to play for the treatment of coronary artery disease.