Search PubMed⌕ Search

Biomedical subjects

Mikael Dellborg

Publications and source records attributed to Mikael Dellborg.

27 records · Page 2Linked to original sources

ST-segment monitoring in patients with acute coronary syndromes.

ST-segment analyses from electrocardiograms during acute coronary syndromes (ACS) have repeatedly shown strong mechanistic links to coronary artery patency and myocardial reperfusion. In these patients, such analyses have also consistently been reported to have close correlations with outcome--correlations superior even to those reported for invasive coronary flow measurements and outcome. Continuous multilead ST-monitoring of patients with ACS provides accurate and noninvasive information on the dynamics of the myocardial reperfusion process over time. This information can be used for improved early diagnostic accuracy, evaluation of treatment efficacy, early risk-stratification, and can be supportive in clinical decision making regarding these patients. Continuous multilead ST-monitoring during ACS is no longer a cumbersome source of more nuisance than benefit, but can be an accurate and useful tool in multicenter clinical trials, as well as in clinical medicine.

Acute Disease↗

Comparison of treatment and outcomes for patients with acute myocardial infarction in Minneapolis/St. Paul, Minnesota, and Göteborg, Sweden.

BACKGROUND: Treatment of acute myocardial infarction (AMI) is changing, and differences in medical practice are observed within and between countries on the basis of local practice patterns and available technology. These differing approaches provide an opportunity to evaluate medical practice and outcomes at the population level. The primary aim of this study was to compare medical care in patients hospitalized with AMI in 2 large cities in Sweden and the United States. A secondary aim was to compare medical outcomes. METHODS: All resident patients (age range, 30-74 years) hospitalized with AMI in Göteborg, Sweden (1995-1996), and a representative population-based sample of all patients with AMI in Minneapolis/St. Paul, Minn (1995). RESULTS: Patients with AMI in Göteborg (GB) were older than patients in Minneapolis/St. Paul (MSP), but fewer patients in GB had a prior history of cardiovascular disease. During the AMI admission, coronary angiography, percutaneous coronary angioplasty (PTCA), and coronary artery bypass grafting (CABG) were performed twice as frequently in MSP than in GB. Echocardiogram and exercise testing were more frequently performed in GB. During hospitalization, beta-blockers were more frequently prescribed in GB, whereas calcium channel blockers, long- and short-acting nitrates, intravenous nitroglycerine, digitalis, aspirin, oral anticoagulants, heparin, and lidocaine were significantly more common in MSP. Thrombolysis, acute PTCA, ACE inhibitors, and diuretics were similar. Reinfarction was higher in men in GB (4% vs 1%, P <.009) and women in GB (3% vs 1%, P = not significant). On discharge, beta-blockers and diuretics were prescribed significantly more often in GB, whereas calcium channel blockers, nitrates, and digitalis were prescribed more often in MSP. Aspirin and ACE inhibitors had similar usage rates. Despite these diagnostic and treatment contrasts, there were no differences in mortality rate at 30 days or after 3 years of follow-up after risk-adjusting for patient baseline differences. CONCLUSION: Comparing patients hospitalized with AMI in MSP and GB, we found marked differences in medical care, with invasive strategies more likely to be used in MSP. This may be the result of historical practice patterns, the healthcare system, and healthcare financing differences. Despite these differences, short- or long-term mortality rates were identical.

Adult↗

Prognostic value of ST-segment resolution-when and what to measure.

AIMS: Analyses of ST-segment resolution during acute myocardial infarction has, during recent years, challenged coronary angiography as gold-standard for predicting myocardial reflow and future risk. We have previously reported that continuous ST-monitoring can be done accurately in the clinical setting. We now set out to compare the prognostic value of previously suggested cut-offs for ST-segment resolution, and determine the times to measure these. METHODS AND RESULTS: We analysed 752 patients with ST-elevation infarction, from the second Assessment of Safety and Efficacy of a New Thrombolytic (ASSENT 2) and ASSENT-PLUS studies, either with vectorcardiography or continuous 12-lead ST-monitoring. All analyses were made blindly by two independent observers. Times to 20, 30, 50 and 70% ST-segment resolution were examined in relation to 30-day mortality.The optimal cut-off for ST-segment resolution analyses was found to be 50%, measured at 60 min. We could hereby identify a large low-risk group, 40% of the population, with only 1.4% 30-day mortality. Furthermore, 88% of deaths were correctly predicted within 1h of observation and treatment. CONCLUSION: Continuous ST-monitoring of patients with acute myocardial infarction yields important prognostic information after 60 min of observation and should be used for very early-risk stratification in these patients.

Aged↗

Low molecular weight heparin (dalteparin) compared to unfractionated heparin as an adjunct to rt-PA (alteplase) for improvement of coronary artery patency in acute myocardial infarction-the ASSENT Plus study.

BACKGROUND: Current thrombolytic-antithrombotic regimens in acute myocardialinfarction (AMI) are limited by incomplete early coronary reperfusion and by reocclusion and reinfarction. We compared the effects of low molecular weight heparin (LMWH) versus unfractionated heparin (UFH) as an adjunct to recombinant tissue-plasminogen activator (alteplase) on coronary artery patency and clinical outcomes in AMI. METHODS: Patients with AMI treated with alteplase (n=439) were randomised to either subcutaneous dalteparin (120 IU/kg every 12h) for 4-7 days or intravenous infusion of UFH for 48 h. Coronary angiography was performed between day 4 and hospital discharge. Clinical events and safety were evaluated until day 30. RESULTS: Overall there were higher thrombolysis in myocardial infarction (TIMI) flows in the infarct related coronary artery in the dalteparin group (p=0.016). The predefined primary end-point, TIMI grade 3 flow, did not reach statistical significance (dalteparin 69.3% versus heparin 62.5%; p=0.163). However, TIMI 0-1 flow (13.4 versus 24.4%; p=0.006) and its combination with intraluminal thrombus (27.9 versus 42.0%; p=0.003) were less common in the dalteparin group. During the period of randomised treatment there were less myocardial reinfarctions in the dalteparin group(p=0.010) but after cessation of dalteparin there were more reinfarctions resulting in no difference in death or MI at 30 days. There were no significant differences in major bleeding or stroke after 30 days. CONCLUSIONS: In alteplase treated AMI adjunctive dalteparin for 4-7 days seems to reduce the risk of early coronary artery occlusion and reinfarction. However, early after cessation of treatment there is a raised risk of events, which might eliminate any long-term gains.

Abciximab↗

Prognosis after acute myocardial infarction continues to improve in the reperfusion era in the community of Göteborg.

BACKGROUND: The objective of this study was to compare the prognosis of nonselected patients who had an acute myocardial infarction (AMI) during 2 time periods in the thrombolytic era and to describe coronary heart disease (CHD) mortality rates in the community of Göteborg during 1990 to 1995. METHODS: Patients aged <75 years who were hospitalized in the community of Göteborg for AMI during 1990 to 1991 (period 1) and 1995 to 1996 (period 2) were compared in terms of history, treatment for AMI, and outcome. Information on CHD mortality rates in the community of Göteborg was gathered from the National Registry of Deaths. RESULTS: The numbers of patients in the 2 cohorts were 926 and 861, respectively. The incidence rate for AMI per 100,000 inhabitants and year was 200 for period 1 and 183 during period 2. During period 2, there was an increased use of percutaneous transluminal coronary angioplasty, coronary artery bypass grafting, angiotensin-converting enzyme inhibitors, heparin, and intravenous nitroglycerin. On the other hand, there was a decreased use of thrombolytic agents, diuretic agents, digitalis, long-acting nitrates, calcium-channel blockers, and lidocaine. The hospital case-fatality rates were 9.4% during period 1 and 6.0% during period 2 (P =.01). The adjusted risk ratio for period 2 versus period 1 was 0.65, with 95% confidence limits of 0.45 to 0.94. The mortality rate over a period of 3 years was 26.5% during period 1 and 17.8% during period 2 (P <.0001). The adjusted risk ratio for period 2 versus period 1 was 0.67, with 95% confidence limits of 0.54 to 0.82. Among inhabitants aged 30 to 74 years in the community of Göteborg, the CHD mortality rate decreased in 1995 as compared with 1990 (age-adjusted odds ratio 0.79, 95% confidence limits 0.68 to 0.92). CONCLUSIONS: For consecutive patients aged <75 years who were hospitalized for AMI in the community of Göteborg, we found that in the thrombolytic era, major changes in medical and nonmedical treatment still took place associated with a continuing decrease in mortality rates during 3 years of follow-up. A similar reduction of CHD mortality rates was seen in the same age group within the community of Göteborg.

Adult↗

Continuous vectorcardiography is superior to standard electrocardiography in the prediction of long-term outcome after thrombolysis in patients with acute myocardial infarction.

BACKGROUND: Thrombolytic therapy results in reperfusion of the occluded coronary vessel in approximately 75% of treated patients with acute myocardial infarction (AMI). Unsuccessful thrombolysis results in impaired outcome. This study was undertaken to evaluate reperfusion assessments with 12-lead standard static electrocardiography (ECG) and continuous vectorcardiography (VCG) in AMI patients treated with thrombolytic therapy, with particular emphasis on the value of these assessments in relation to long-term outcome. METHODS: ST-recovery analysis 90 and 180 min after the start of thrombolytic therapy was performed by repeated ECG and by VCG in 63 AMI patients. Median follow-up was 255 days. RESULTS: No significant differences in long-term outcome were found between patients with or without obtained reperfusion, as assessed by ECG. For VCG, we found significant elevated relative risks for experiencing death (relative risk = 11.00, confidence interval = 2.70-44.90); P = 0.0008 for the group with ST-vector magnitude recovery of less than 50% at 90 min from start of thrombolytic therapy. CONCLUSION: We demonstrated that early reperfusion assessment with VCG enables the prediction of long-term outcome and is superior to reperfusion assessment with standard static ECG in this regard. We therefore recommend continuous ischemia monitoring of AMI patients treated with thrombolytic therapy as a routine procedure.

Denmark↗

Computerized vectorcardiography telemetry: a new device for continuous multilead ST-segment monitoring of ambulatory patients. A preliminary report.

BACKGROUND: Continuous vectorcardiography ST-segment monitoring has become a well-established method in the surveillance of patients with acute myocardial ischemia. However, immobility of the vectorcardiography technique prevents monitoring of patients during ambulatory activities. Computerized vectorcardiography telemetry (CVT) with the capacity of real-time ST-segment analysis has been developed in an attempt to overcome this shortcoming. Recent data, however, indicate that changes in body position occasionally lead to pseudo-ischemic ST-segment changes during continuous ST-segment monitoring. AIMS: This report describes the technical features of the CVT system, presents clinical examples using CVT, and assesses the influence of changes in body position on ST-vector magnitude (ST-VM) during CVT, respectively. METHODS: Clinical cases involving CVT are presented. The influence of changing body position during CVT monitoring was evaluated on 24 patients with suspected acute coronary syndromes, i.e., unstable angina or acute myocardial infarction. Each patient performed a specific body positional schedule. RESULTS: We present three discrete clinical cases where CVT provided early and valuable evidence of ongoing myocardial ischemia. The consequences of different recumbent and ambulatory body positions on ST-VM during CVT monitoring appear to be limited. CONCLUSION: Computerized vectorcardiography telemetry is a promising new tool for disclosing residual myocardial ischemic activity during the mobilization phase of patients with acute coronary syndromes. The clinical value of CVT needs further investigation in future trials.

Angina, Unstable↗