STEMI is usually caused by acute thrombotic occlusion at the site of a ruptured atherosclerotic plaque. Early recanalization of the artery has been well established as the optimal treatment. As described by Bradley, et al,2
small reductions in time at various stages of the process added up to a significant decrease in the total D2B time, in our experience. Acceptable time limits are noted in . Any such subdivisions of the total D2B time that are longer than acceptable are investigated, including discussion with individuals and departments involved.
This approach resulted in a steady improvement in the measures being evaluated, as noted above. In fact the improvement started before the program was formally instituted, presumably as a result of increased awareness of existing problems while planning was in progress. Following the initiation of the program, in May, 2007, improvement continued over the next year, as caregivers became increasingly familiar with the protocol, and has largely been maintained. Maintenance of a satisfactory D2B time has been an ongoing challenge, given a 24/7 operation involving a busy emergency department, and vigilance is needed to insure continued success. Continued regular meetings of the D2B committee, with prompt feedback to involved individuals, has been felt to be the key to success. While we have been gratified to achieve the results described, we hope to effect further improvements in patient outcomes, by incorporating new innovations in cathlab and adjunctive techniques. In a process where time is crucial, there is an advantage to a uniform approach by all operators, and to using methods that do not risk causing delay. These considerations need to be balanced against the potential advantages of modifying the process, to incorporate changes shown to improve prognosis. Such newer techniques were used in a small minority of the cases under review, and are not considered to have impacted outome of the group as a whole. They include:
- Radial artery as access site. Reduced complications and improved prognosis have been reported with this approach in the STEMI subset of the RIVAL study.4 While our cardiologists use radial access for most elective cases, the femoral artery has usually been used for STEMI patients, because of greater predictability of rapid access. An appropriate process may be to allot a period of perhaps 5 minutes, strictly timed, for radial access, with default to femoral approach if not successful in that time.
- Antithrombotic measures. The use of bivalirudin, in place of heparin and a glycoprotein IIb/IIIa inhibitor has been shown to reduce hemorrhagic complications and mortality,5 and has been increasingly employed. Selection of oral anti-platelet therapy is also important, especially when bivalirudin is used during the intervention. Prasugrel has been associated with fewer recurrent infarctions and ischemic complications than clopidogrel, probably without increased bleeding risk.6 Ticagrelor use has reduced mortality and decreased stent thrombosis compared with clopidogrel, without increase in major bleeding.7 These newer agents are likely to be increasingly preferred in selected cases.
- Thrombus aspiration. Improved reperfusion has been reported when thrombus is aspirated before angioplasty,8 though published results of ongoing benefit have been variable. This technique is likely to be employed on a case by case basis, depending on anatomic findings. Because this will delay the actual balloon inflation, the term “door-to-device” has been suggested in place of “door-to-balloon” to more accurately reflect the time to arterial recanalization.