Regional implementation of the NWC guideline on ST-elevation myocardial infarction: Report from the Task Force Prehospital Triage Zuidoost Brabant (PHT ZoB).

BACKGROUND: The NVVC guideline on ST-elevation myocardial infarction forms the basis for the regional prehospital triage (PHT) project in Zuidoost Brabant. In this project diagnosis and treatment strategies are determined in the ambulance. AIM: To summarise quality assessment and clinical results after one year. METHODS: We evaluated the protocol and patient record form, the patient's call, assignment of tasks, diagnosis, treatment, time intervals, information to hospitals, cooperation and data transmission. Time delays were compared with time delays in a regional dry run before the start of the project and with time delays reported in the literature. RESULTS: Patients still wait over one hour before seeking medical attention. The GP received the majority (65%) of patient calls. In half of all cases (51%), GPs call the ambulance centre only after they have seen the patient. When the patient calls the ambulance centre (35%), information to the GP is either prompt or absent. In 77% of calls to 112 it remains unclear whether the GP was informed at all. The treatment strategy was correct in 97% of cases. Time between symptoms and call decreased in comparison with our local preliminary investigation. Quality assessment after one year shows protocol deviations that are either logical procedural improvements or correctable flaws with no substantial negative influence. CONCLUSION: Short-term clinical results are good, but structured follow-up is needed to reduce mortality in the long term, especially after thrombolysis. A guideline is a snapshot of a dynamic process. The PHT project allows rapid adaptations to be made to new paradigms.

Fibrinolysis and primary PCI for ST-elevation myocardial infarction: call for a more refined perspective.

The latest meta-analysis comparing fibrinolysis with primary percutaneous intervention (PCI) has fuelled the discussion regarding the best reperfusion therapy for acute ST-elevation myocardial infarction. As far as patients presenting to centres with intervention facilities are concerned, the superiority of primary PCI has been unequivocally demonstrated. However, only a small proportion of patients with St-elevation myocardial infarction primarily present to an intervention centre, the majority go to a hospital without these facilities. The optimal reperfusion strategy for patients presenting to a nonintervention centre or for patients presenting in the prehospital setting has been studied less extensively and the question remains as to whether all these patients should be transferred to an intervention centre to undergo primary PCI. The available data to date on interhospital transport for primary PCI do show a mortality benefit for primary PCI. Yet, as far as inferences to clinical practice are concerned, it remains to be seen whether these studies are truly representative: almost half of patients in the transportation trials received streptokinase, they were treated relatively late, and the subsequent revascularisation strategy was rather conservative. The impact of primary PCI as compared with prehospital fibrinolysis in patients presenting in the prehospital setting has so far only been addressed in the randomised CAPTIM trial, without significant differences in outcome. Additional studies are warranted, with early treatment as primary focus. For patients presenting to non-intervention centres or prehospitally, the impact of triage, and of combined pharmaco-invasive reperfusion strategies are promising fields of further exploration.

Abnormal epicardial coronary resistance in patients with diffuse atherosclerosis but "Normal" coronary angiography.

BACKGROUND: Coronary arteries without focal stenosis at angiography are generally considered non-flow-limiting. However, atherosclerosis is a diffuse process that often remains invisible at angiography. Accordingly, we hypothesized that in patients with coronary artery disease, nonstenotic coronary arteries induce a decrease in pressure along their length due to diffuse coronary atherosclerosis. METHODS AND RESULTS: Coronary pressure and fractional flow reserve (FFR), as indices of coronary conductance, were obtained from 37 arteries in 10 individuals without atherosclerosis (group I) and from 106 nonstenotic arteries in 62 patients with arteriographic stenoses in another coronary artery (group II). In group I, the pressure gradient between aorta and distal coronary artery was minimal at rest (1+/-1 mm Hg) and during maximal hyperemia (3+/-3 mm Hg). Corresponding values were significantly larger in group II (5+/-4 mm Hg and 10+/-8 mm Hg, respectively; both P<0.001). The FFR was near unity (0.97+/-0.02; range, 0.92 to 1) in group I, indicating no resistance to flow in truly normal coronary arteries, but it was significantly lower (0.89+/-0.08; range, 0.69 to 1) in group II, indicating a higher resistance to flow. In 57% of arteries in group II, FFR was lower than the lowest value in group I. In 8% of arteries in group II, FFR was <0.75, the threshold for inducible ischemia. CONCLUSION: Diffuse coronary atherosclerosis without focal stenosis at angiography causes a graded, continuous pressure fall along arterial length. This resistance to flow contributes to myocardial ischemia and has consequences for decision-making during percutaneous coronary interventions.

Impaired vasodilator response to atrial natriuretic factor in IDDM.

Diabetes mellitus has been associated with both elevated plasma concentrations of the natriuretic and vasorelaxant hormone atrial natriuretic factor and with a reduced natriuretic response to this hormone. We now hypothesize that the vasodilator response to atrial natriuretic factor is attenuated in IDDM. Forearm vasodilator responses to the infusion of six increasing dosages of atrial natriuretic factor into the brachial artery were registered by venous occlusion strain gauge plethysmography in 10 patients with uncomplicated IDDM and in 10 age-, sex-, and weight-matched control subjects. Baseline levels of blood pressure, forearm blood flow, and plasma concentrations of atrial natriuretic factor were not different between control subjects and patients with diabetes. In control subjects, atrial natriuretic factor induced a percentage fall in the forearm vascular resistance of -29 +/- 5% at the lowest to -72 +/- 4% at the highest infusion rate. In patients with diabetes this fall was significantly attenuated, measuring -2 +/- 7 and -45 +/- 4%, respectively, (P < 0.001 vs. control subjects). During infusion of atrial natriuretic factor into the brachial artery, the calculated regional production of cGMP (second messenger of atrial natriuretic factor) increased from 1.2 +/- 1.1 to 22.8 +/- 4.8 pmol.min-1 x 100 ml-1 in the control subjects, whereas hardly any change occurred in the patients with diabetes (from -2.1 +/- 1.2 to 2.9 +/- 4.7 pmol.min-1 x 100 ml-1). Furthermore, both control and diabetic subjects demonstrated an equal forearm vasodilator response to increasing infusion rates of the control vasodilator sodium nitroprusside. We conclude that uncomplicated IDDM is associated with a specific reduction in the vascular responsiveness to atrial natriuretic factor.(ABSTRACT TRUNCATED AT 250 WORDS)