[Interventional treatment of acute myocardial infarct]. / Interventionelle Behandlung des akuten Myokardinfarkts.

BACKGROUND: Randomised trials have shown that primary percutaneous angioplasty (PTCA) may offer advantages over thrombolysis in treating acute myocardial infarction (vessel patency is achieved more often, mortality and reinfarction rate are lower, cerebrovascular accidents are less frequent). Data from several foreign registries have been less clear. Up to now no registry data have been available for Switzerland. Data from registries are very important in planning optimal treatment under "real world" conditions. METHOD: All patients receiving acute PTCA during the first 24 hours of acute myocardial infarction were prospectively included in a registry at a single centre. We assessed times until revascularisation, as well as clinical, angiographic and outcome data. RESULTS: 503 patients (age 59 +/- 12 years, 15% women) were included from 1. 1. 1995 to 30.6.2000. Primary PTCA was performed in 334 patients, and rescue PTCA in 169. Diabetes mellitus was present in 36% of the total. Multivessel disease was present in 61%, anterior infarction in 36%, and 16% were in cardiogenic shock before intervention. The pre-hospital delay was 2:12 h (median). In-hospital decision delay (hospital admission until contact to cardiologist) in patients with primary PTCA was 31 minutes (median). The time from vessel puncture to recanalisation was 19 minutes (median). 273 patients were transferred for coronary angiography and intervention by other hospitals (218 by ground ambulance, 55 per helicopter transfer). The total transfer time (calculated from time of decision to arrival in the catheterization laboratory) was 57 minutes (median). PTCA was successful angiographically in 97% and TIMI 3 flow was obtained in 93% of all patients. Hospital mortality was low in view of the high proportion of patients in cardiogenic shock prior to PTCA (mortality in shock patients was 33%). Mortality in patients without pre-existing cardiogenic shock was 2%. CONCLUSION: Patients with acute myocardial infarction, especially high-risk patients, can be treated successfully by acute PTCA around the clock in Switzerland, in accordance with the strict international recommendations for time delays. The treatment results are similar to those in randomised trials. Transfer of patients from referral hospital is safe, with acceptable delays. Optimisation of the decision process and transport logistics may further improve outcome by reducing the total ischaemia time.

Hospital transfer for primary coronary angioplasty in high risk patients with acute myocardial infarction.

OBJECTIVE: To investigate the feasibility, safety, and associated time delays of interhospital transfer in patients with acute myocardial infarction for primary percutaneous transluminal coronary angioplasty (PTCA). DESIGN AND PATIENTS: Prospective observational study with group comparison in a single centre. 68 consecutive patients with acute myocardial infarction transferred for primary PTCA from other hospitals (group A) were compared with 78 patients admitted directly to the referral centre (group B). MAIN OUTCOME MEASURES: Patient groups were analysed with regard to baseline characteristics, time intervals from onset of chest pain to balloon angioplasty, hospital stay, and follow up outcome. RESULTS: Patients in group A presented with a higher rate of cardiogenic shock initially than patients in group B (25% v 6%, p = 0.01) and had been resuscitated more frequently before PTCA (22% v 5%, p = 0.01). No deaths or other serious complications occurred during interhospital transfer. Median transfer time was 63 (range 40-115) minutes for helicopter transport (median 42 (28-122) km, n = 14), and 50 (18-110) minutes by ground ambulance (median 8 (5-68) km, n = 54). The median time interval from the decision to perform coronary arteriography to balloon inflation was 96 (45-243) minutes in group A and 52 (17-214) minutes in group B (p = 0.0001). In transferred patients (group A) the transportation associated delay and the longer in-hospital median decision time (50 (10-1120) minutes in group A v 15 (0-210) minutes in group B, p = 0.002) concurred with a longer total period of ischaemia (239 (114-1307) minutes in group A v 182 (75-1025) minutes in group B, p = 0.02) since the beginning of chest pain. Success of PTCA (TIMI 3 flow in 95% of all patients), in-hospital mortality (7% v 9%, mortality for patients not in cardiogenic shock 0% v 4%), and follow up after median 235 days was similarly favourable in groups A and B, respectively. Only one hospital survivor (group A) died during follow up. CONCLUSION: Interhospital transport for primary PTCA in high risk patients with acute myocardial infarction is safe and feasible within a reasonable period of time. Short and medium term outcome is favourable. Optimising the decision process and transport logistics may further improve outcome by reducing the total time of ischaemia.

Dual chamber pacing with a single-lead DDD pacing system.

The successful application of single-lead VDD pacing during the last few years has generated the idea of single-lead DDD pacing. Preliminary data from several single-lead VDD studies attempting to pace the atrium by a floating atrial dipole are unsatisfactory, causing an unacceptably high current drain of the device. We studied the feasibility as well as the short- and long-term stability of atrioventricular sequential pacing, using a new single-pass, tined DDD lead. In eight consecutive patients (age 73+/-16 years) with symptomatic higher degree AV block and intact sinus node function, this new single-pass DDD lead was implanted in combination with a DDDR pacemaker. Correct VDD and DDD function was studied at implantation; at discharge; and at 1, 3, and 6 months of follow-up. At implant, the atrial stimulation threshold was 0.6+/-0.1 V/0.5 ms. During follow-up, the atrial pacing thresholds in different every day positions averaged 2.1+/-0.5 V at discharge, 2.9+/-0.5 V at 1 month, 3.8+/-0.4 V at 3 months, and 3.4+/-0.4 V at 6 months (pulse width always 0.5 ms). The measured P wave amplitude at implantation was 4.5+/-2.2 mV; during follow-up the telemetered atrial sensitivity thresholds averaged 2.1+/-0.3 mV. Phrenic nerve stimulation at high output pacing (5.0 V/0.5 ms) was observed in three (38%) patients at discharge and in one (13%) patient during follow-up; an intermittent unmeasurable atrial lead impedance at 3 and 6 months follow-up was documented in one (13%) patient. This study confirms the possibility of short- and long-term DDD pacing using a single-pass DDD lead. Since atrial stimulation thresholds are still relatively high compared to conventional dual-lead DDD pacing, further improvements of the atrial electrodes are desirable, enabling lower pacing thresholds and optimizing energy requirements as well as minimizing the potential disadvantage of phrenic nerve stimulation.

[C-reactive protein and relative lymphocytopenia: early markers of acute myocardial infarction?]. / C-reaktives Protein und relative Lymphozytopenie: Frühmarker des akuten Myokardinfarkts?

OBJECTIVE: Recent data suggest that relative lymphocytopenia and elevated C-reactive protein (CRP) are early markers of myocardial infarction. We tested these two parameters to predict myocardial infarction before elevation of creatine kinase. METHODS: Over a two-year period, 260 patients presented at the emergency room of Männedorf Hospital with suspicion of unstable angina or myocardial infarction. 197 patients were excluded because of intercurrent conditions associated with an acute-phase response or changes in leukocyte counts, as well as patients with established myocardial infarction (creatine kinase elevation at entry). The remaining 63 patients were reviewed for relative lymphocytopenia (< 20.3%) and C-reactive protein levels > 5 mg/l at admission. RESULTS: Elevated levels of C-reactive protein were found in 8 of 20 patients (40%) with unstable angina and in 29 of 43 patients (67%) with myocardial infarction. A value for C-reactive protein > 5 mg/l on admission had a sensitivity of 67% and a predictive value of 78% for subsequent myocardial infarction. Relative lymphocytopenia was found in 2 patients (10%) with unstable angina and in 19 patients (44%) with myocardial infarction. The positive predictive value of both markers diagnosing myocardial infarction was 93% compared to 78% of elevated CRP or 90% of relative lymphocytopenia. In contrast, the sensitivity of both markers combined was 33%. CONCLUSIONS: At present, elevation of C-reactive protein and relative lymphocytopenia allow early diagnosis of myocardial infarction. However, the markers' sensitivity is relatively low.

[Influence of various antithrombotic therapy methods on the incidence of subacute coronary stent occlusions, hemorrhagic complications and length of hospitalization]. / Einfluss verschiedener antithrombotischer Therapien auf die Häufigkeit von subakuten koronaren Stentverschlüssen, Blutungskomplikationen und Hospitalisationsdauer.

BACKGROUND: The clinical benefit of coronary stenting is reduced by the risk of thrombotic stent occlusion as well as hemorrhagic complications of intensive antithrombotic therapy. We compared the influence of different antithrombotic therapies on the incidence of post-interventional complications and in-hospital stay duration. METHODS: After successful placement of a coronary stent, 334 consecutive patients were given different antithrombotic treatments in addition to aspirin 100 mg/d indefinitely: (1) phenprocoumon for 3 months (n = 47), (2) low molecular weight heparin 2 x 100 U/kg/d s.c. for 4 weeks (n = 90), (3) ticlopidine 2 x 250 mg/d and low molecular weight heparin 2 x 100 U/kg/d s.c. for 4 weeks (n = 72) and (4) ticlopidine 2 x 250 mg/d for 4 weeks (n = 125). RESULTS: Major events were subacute stent thrombosis in 17 patients (5%), and severe hemorrhagic complication in 20 patients (5.9%). The incidence of subacute stent thrombosis in groups 1 to 4 was 10.6%, 11%, 1.4% and 0.8% respectively. The use of ticlopidine was associated with a significant lowering of stent occlusions in univariate and multivariate analysis (p = 0.0013). Additional uni- and multivariate predictors were stent placement as a "bail-out" procedure (p = 0.033) and in patients with acute coronary syndrome (p = 0.049). Anticoagulant therapy was associated with a higher incidence of severe hemorrhagic complications (p < 0.01) and a prolonged in-hospital stay (p = 0.01). CONCLUSIONS: These results confirm that anti-thrombotic therapy with aspirin and ticlopidine combines low rates of subacute stent occlusion and hemorrhagic complications. Treatment with phenprocoumon and low molecular weight heparin does not improve the rate of subacute stent occlusion but increases hemorrhagic complications. Very low rates of stent occlusion permit short in-hospital stays with concomitant reduction in cost.

[Anti-thrombosis therapy following coronary stent implantation]. / Antithrombotische Therapie nach koronarer Stentimplantation.

Coronary stenting has proved effective in the management of acute or imminent vessel closure after coronary balloon angioplasty. Stent implantation has also been shown to reduce the rate of restenosis. Opposing these benefits, subacute thrombotic stent occlusion is a serious and life-threatening complication which occurred at alarmingly high rates in early series. This paper reviews the contemporary strategies in the prevention of stent thrombosis, emphasizing improved procedural technique and optimal antiplatelet therapy. It is shown that these new preventive strategies led to acceptable subacute stent thrombosis rate of < or = 1%.

[Hyperventilation test: a noninvasive screening test for coronary vasospasm]. / Der Hyperventilations-Test: ein nicht-invasiver Suchtest für koronare Vasospasmen.

3 patients with coronary vasospasms in different clinical situations are presented. One patient had typical Prinzmetal angina but coronary arteries without significant stenosis. One patient without typical angina pectoris showed sudden significant ST elevations on anterior and lateral ECG tracings accompanied by typical ischemic chest pain. At angiography, a 70% LAD stenosis was found without high degree lesions. One patient (aged 30 years) had a documented anterior infarction with angiographically normal coronary arteries. In all these cases coronary vasospasms were recognized as the underlying cause of the symptoms. All the patients were treated with calcium channel blockers and have been asymptomatic since. Currently available data comparing the diagnostic value of hyperventilation with other tests for coronary vasospasms, such as ergonovine or acetylcholine, are discussed. The hyperventilation test can be recommended as the first test in the work up of suspected vasospastic angina pectoris.

Ischemic heart disease: assessment with gadolinium-enhanced ultrafast MR imaging and dipyridamole stress.

The potential of magnetic resonance (MR) imaging for the detection of myocardial perfusion abnormalities in patients with coronary artery disease has not been fully explored. A feasibility study was conducted in 10 patients with a novel approach to determine whether myocardial ischemia can be assessed with MR imaging and dynamic first-pass bolus tracking enhanced with gadolinium tetraazacyclododecanetetraacetic acid (DOTA). Three tomographic planes were acquired before and after pharmacologic stress with dipyridamole, with use of the bolus-tracking series at rest as a reference. The change in myocardial rate of enhancement was compared with the results obtained by means of the established methods, exercise thallium scintigraphy and coronary angiography. Detection of ischemic regions with MR imaging showed a sensitivity, specificity, and diagnostic accuracy of 65%, 76%, and 74%, respectively. Ultrafast MR imaging can be used to detect regions of myocardial ischemia.

Treatment of internal mammary artery malperfusion syndrome by additional venous graft: early postoperative angiographic results.

BACKGROUND: Internal mammary artery malperfusion syndrome is caused by an acute imbalance between myocardial demand and nutritional support through the mammary artery. METHODS: We performed early angiography in 11 consecutive patients in whom the perioperative course suggested mammary artery malperfusion. All patients received an additional saphenous vein graft distally to the mammary artery anastomosis. RESULTS: Postoperative angiography revealed patent mammary artery and vein graft in 10 patients (three with a markedly reduced caliber of the arterial graft). CONCLUSION: Additional vein graft is the treatment of choice in mammary artery malperfusion syndrome; it does not lead to occlusion of the internal mammary artery.