[Primary percutaneous coronary intervention (PCI) or thrombolysis in acute myocardial infarction [Editorial].].
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Publications and source records attributed to R Danielsen.
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PURPOSE: To evaluate potential changes in clinical indications and the composition of the patient population undergoing percutaneous coronary intervention (PCI) in Iceland from 1987 to 1998. Furthermore, to assess changes in success rate and major complications for the procedure during the study interval in a small nation with one PCI centre. MATERIAL AND METHODS: The first PCI was performed in Iceland in May 1987. A registry has been kept from the start that includes clinical and procedural data, and records of complications and mortality. During the study interval a total of 2440 PCIs were performed. The annual procedure rate was low at first, with a steep rise during the last years. Based on procedural changes over the years the study interval was divided into three periods: I. 1987-1992 (471 procedures); the learning years, II. 1993-1995 (796 procedures); increasing number of PCIs and the method established, III. 1996-1998 (1173 procedures); increasing use of stents and new antiplatelet regime used. RESULTS: From period I to III, the rate of elective PCI declined from 82% to 52% (p<0.001), subacute procedures increased from 14% to 44% (p<0.001), acute PCI from 0.8% to 3% (p<0.05), and ad hoc procedures from 0.4% to 28% (p<0.001). This reflects an increase in PCI on patients with acute coronary syndromes, as the ratio of patiens with unstable angina increased from 15% to 36% (p<0.001). Also, 1-vessel PCI decreased proportionally from 93% to 83%, while 2 and 3 vessel procedures increased from 7% to 17% (p<0.001). The proportion of patients 70 years or older increased from 7% to 27% (p<0.001). Still, the success rate for PCI increased from 83% to 93% (p<0.001) and the use of stents rose sharply from 0% to 56%. The ratio of PCI due to restenosis declined somewhat between period II and III, from 15% to 12% (p=0.06). Simultaneously, the rate of acute coronary bypass surgery after PCI decreased from 4.2% to 0.2% (p<0.001) and significantly fewer patients had elevated creatinine kinase levels (4.0% vs 2.7%, respectively, p<0.05). However, clinical acute myocardial infarction after PCI remained similar at 1.3% and 0.9%, and the in hospital mortality was 0.6% and 0.4%. CONCLUSIONS: On a national basis the rate of PCI in Iceland is amongst the highest in Europe. Thus, in 1998, when the population in Iceland was 275,000, 453 PCIs were done (1647 procedures per million inhabitants). An increased number of subacute and acute PCIs is carried out, more complicated procedures are performed in patients with widespread disease, and the patient population is growing older. Still, the success rate is high and the frequency of complications and mortality relatively low.
Fibrinogen (FBG) and total coagulation factor VII (FVIIc) concentrations are higher in those patients with coronary artery disease who are at increased future risk of acute ischemic events. The relationship between activated factor VII (FVIIa) and cardiovascular events, however, has not been intensively studied. Data were collected from 401 consecutive patients who underwent coronary angiography because of suspected coronary artery disease. Conventional risk factors FVIIc, FVIIa and FBG were assessed in relation to the severity of coronary artery disease, left ventricular ejection fraction, and previous clinical events. A strong positive correlation was found between FVIIa and FVIIc (p < 0.001), but neither FVIIa nor FVIIc correlated with FBG. No correlation was found between FVIIa, FVIIc or FBG levels and stenosis score for the severity of coronary artery disease, and all were similar in patients with stable or unstable angina pectoris. Multivariate regression analysis showed FVIIc to be higher in women (p = 0.004), and positively related to triglycerides (p = 0.001) and HDL cholesterol (p = 0.006), but not to a previous myocardial infarction or total cholesterol. FVIIa, on the other hand, was lower in patients with a previous myocardial infarction (p = 0.004), higher in women (p = 0.001) and those that previously had undergone percutaneous transluminal coronary angioplasty (p = 0.039), and positively related to total cholesterol (p = 0.011), duration of coronary artery disease (p = 0.032), and smoking (p = 0.008). FBG was positively associated with a previous myocardial infarction (p = 0.013), hypertension (p = 0.016), smoking (p = 0.005), and the thrombocyte count (p < 0.001). Finally, stepwise logistic regression analysis verified a previous myocardial infarction to be negatively associated with FVIIa (p = 0.03), and positively with FBG (p = 0.03), total cholesterol (p = 0.02), and the severity of coronary artery disease (p < 0.001). In conclusion, in patients suspected of coronary artery disease undergoing cardiac catheterization, FVIIa was decreased and FBG increased in those who had a previous myocardial infarction. FVIIa, FVIIc, or FBG levels were not, however, related to the severity of coronary artery disease, and they were similar in patients with stable or unstable angina pectoris.
UNLABELLED: The aim of the study was to evaluate and compare the hemodynamic and electrocardiographic effects following injection of the non-ionic, low-osmolar contrast medium iopentol (Imagopaque 350, Nycomed Imaging AS, Oslo, Norway) and the ionic, hyper-osmolar contrast medium metrizoate meglumine-Na-Ca (Isopaque Coronar 370, Nycomed Imaging AS, Oslo, Norway) when used for left ventricular angiography. The study was performed in a double-blind, randomized manner in 82 patients with severe coronary heart disease. The patients who received iopentol experienced less adverse events and subjective discomfort of lesser intensity than those who received metrizoate (p = 0.0001). Both contrast media induced a biphasic change in left ventricular (LV) systolic pressure, with an initial fall followed by a prolonged rise, but the alterations were statistically significantly more pronounced with metrizoate than with iopentol. The changes in LV end-diastolic pressure (p = 0.023), and LV negative dP/dt (p = 0.002) were significantly more pronounced with metrizoate than with iopentol. Cardiac output and heart rate increased more with metrizoate, while stroke volume was equally increased by both agents. A prolonged increase in the QT-interval, throughout the 10-min observation period, was seen only after injection of metrizoate (p = 0.0006 for comparison between contrast media). CONCLUSION: Iopentol was well tolerated and induced markedly less severe hemodynamic and electrocardiographic alterations than did metrizoate in patients with severe coronary heart disease.
Since 1967 the Reykjavík study has monitored coronary artery disease and its risk factors in randomly selected cohorts. From 1979 to 1984, 3246 men and 3545 women aged 45-74 years were studied. Routine biplane chest X rays were assessed by a radiologist who noted the presence or absence of aortic calcification (AC), but had no detailed knowledge of the subjects. Overall, AC was diagnosed in 283 (8%) women, but in only 54 of the men (1.7%). In the women, the prevalence of AC increased from 2.0% at age 45-49 years to 17.1% at the age of 70-74 years, while in men it was 0 and 8.3%, respectively. In women, multivariate analysis of risk factors showed AC to be positively related to systolic and negatively related to diastolic blood pressure, indicating a potential relation to pulse pressure. Furthermore, AC was independently associated with age, drug treatment for hypertension, nonfasting blood sugar, use of antidiabetic drugs, total serum cholesterol levels, and the amount of smoking. Too few men had AC for multivariate assessment of risk factors. In addition, in women AC was also related to a previous myocardial infarction (p < 0.05), mortality from coronary artery disease (p < 0.01), and the presence of intermittent claudication (p < 0.01). In men, however, AC was related only to total mortality (p < 0.05). Thus, these data show AC to be more prevalent in women, independently associated with recognized atherosclerotic risk factors, and a potential marker for coronary and peripheral artery disease.
To examine left ventricular (LV) myocardial perfusion and function, in systemic sclerosis. Myocardial perfusion was assessed at rest, during cold exposure, and at peak exercise in 10 patients with systemic sclerosis. Seven of the 10 patients were examined with Doppler echocardiography; before and after long-term diltiazem treatment. Compared with average resting values, isotope uptake was increased by 48% after exercise, compared with cold exposure the exercise value was increased by 35%. After 11 months of diltiazem treatment there was no change in myocardial uptake, compared with respective values before treatment. Doppler echocardiography showed an increase in LV end-diastolic diameter, fractional shortening, and left ventricular outflow tract velocity, after treatment. This indicates that long-term diltiazem treatment does not increase myocardial perfusion at rest, post-exercise, or during cold exposure. On the other hand diltiazem treatment may improve left ventricular performance.
Through use of primary and secondary data sources for registration and validation, the incidence and prevalence of Type 1 (insulin-dependent) diabetes mellitus in children aged 0-14 years in Iceland has been completely ascertained for the years 1970-1989. The age-adjusted mean annual incidence per 100,000 for the 20-year period was 9.4 (95% confidence interval 7.8-11.3); similar for boys (9.9; 7.7-12.7) and girls (8.8; 6.7-11.5). Between 1970-1979 the incidence was 8.0 (6.0-10.6) and between 1980-1989 it was comparable at 10.8 (8.4-13.8) (p greater than 0.10). By Poisson regression analysis the variation in incidence was related to age at diagnosis (p less than 0.001), while a linear trend for calendar year at diagnosis did not reach statistical significance (p = 0.07). A quadratic curve, however, better described the temporal variation in incidence (p less than 0.05). The total prevalence per 1,000 by the end of 1979 and 1989 was similar, 0.45 (0.30-0.65) and 0.57 (0.40-0.79), respectively. In conclusion, this study confirms that both the incidence and prevalence of childhood Type 1 diabetes in Iceland are low compared to the other Nordic countries. The findings may suggest a causative role for environmental factors that are not related to latitude or ambient temperature.
It has recently been claimed that lack of sodium in nonionic contrast media may increase the risk of ventricular arrhythmias during coronary angiography. Thus, the influence of sodium addition to the nonionic contrast medium iohexol was studied in 75 patients with severe coronary heart disease. The study design was randomized, parallel and double-blind, and iohexol was given either with or without addition of NaCl (28 mmol/l). Both formulations induced a transient drop in arterial blood pressure, and prolongation of the QT interval and QRS duration at 10 s only (p less than 0.01). The electrical QRS axis was significantly changed by the coronary artery injections after 10 s, but not later. No differences between iohexol with and without NaCl were observed for any of the variables studied. No serious arrhythmias were observed. Thus, the addition of NaCl (28 mmol/l) to iohexol did not influence the electrocardiographic or hemodynamic changes induced by iohexol during coronary angiography.
Ten subjects performed 4 maximal exercise tests to evaluate reproducibility and effects of treadmill inclination on submaximal and maximal oxygen consumption. They performed a standard Bruce protocol twice, and 1 protocol with progressive speed increase with constant, or without, inclination. At maximal exercise there was no significant difference between the protocols in oxygen consumption, respiratory gas exchange ratio, minute ventilation, plasma lactate, serum potassium or heart rate. Exercise time and treadmill distance were shorter than Bruce protocol with inclination, and considerably prolonged without. Reproducibility for Bruce protocol was good for group comparison of oxygen consumption throughout exercise. The individual variations for oxygen consumption were small at maximal exercise, but were considerable at rest and at the lowest exercise steps, this was slightly improved by analysing longer sampling time. Thus, measurement of oxygen consumption is reliable for group analysis, but interpretation must be careful in individuals unless maximal exercise is obtained. Treadmill inclination may be adjusted according to individual preferences.
The main symptoms of aortic stenosis (AS), angina pectoris, dyspnoea, and syncope/effort dizziness, are thought to reflect the severity of AS. This assumption is based on studies in relatively young patients, and may not apply to older age groups. Thus, in 100 consecutive adults (age 41-79 years) referred to cardiac catheterization with suspected AS, clinical and haemodynamic variables were assessed in relation to significant (less than or equal to 0.50 cm2 m-2) (n = 70) and nonsignificant AS (n = 30), and to symptoms. Prevalence of symptoms, functional class, and systolic murmur grade greater than or equal to 3, was similar in the groups. However, patients with significant AS more often had an abnormal second heart sound, electrocardiographic left ventricular (LV) hypertrophy with strain, severe echocardiographic aortic valve calcification, and increased LV wall thickness. Multivariate analysis identified an abnormal second heart sound, and aortic calcification grade, as independent predictors of significant AS. When the Doppler mean gradient was added to the analysis, it became the best predictor. Angina pectoris (n = 74) was related to coronary artery disease, but not to severity of AS. However, 31% of patients without angina also had coronary artery disease. Dyspnoea (n = 69) was only related to age, and syncope/effort dizziness (n = 26) was more frequent in women. Functional class grade was not related to severity of AS. Thus, in adults with assumed symptomatic AS, clinical symptoms do not predict severity of AS. Therefore, the decision for valve replacement should rely on Doppler assessment of the severity of AS. Furthermore, in adults with AS, coronary artery disease cannot be excluded without selective coronary angiography.
We compared the levels of various metabolic indicators in arterial and venous forearm blood during maximal treadmill leg exercise, and the subsequent 9 min in nine volunteers aged 31-56 years. At maximal exercise plasma lactate was 13.2 +/- 3.1 mmol l-1 arterially, while venous was 41% lower, but increased more than arterial after exercise. There was a linear relationship between arterial and venous samples during and after exercise, but not at baseline. Plasma pyruvate increased on the arterial side from 49 +/- 8 to 172 +/- 30 mumol l-1 at maximal exercise, maximal venous was 21% lower. Free fatty acids were not different at rest, but decreased during exercise by 52 and 38% on the arterial and venous side. There was no relationship between arterial and venous levels. Changes in these three variables occurred significantly earlier on the arterial side. Arterial cyclic AMP rose from 97.3 +/- 28.4 to 262.7 +/- 67.5 nmol l-1 from rest to exercise, and was linearly inversely related to the decrease in free fatty acids. The mean venous pH was lower than arterial at rest, but was the same as arterial at maximal exercise and after. Thus, venous plasma lactate and pyruvate, but not free fatty acids, are linearly related to arterial measurements during maximal exercise, while pH is identical. Non-working muscle modifies exercise-induced changes, and therefore venous and arterial forearm blood sampling give more information than either alone.
Increased lung uptake of thallium-201 during exercise has been suggested to indicate left ventricular dysfunction. The normal lung thallium-201 uptake, clearance and lung/myocardial uptake ratio were studied prospectively in 7 healthy men. Initial and delayed (3 h) images were quantitated by computer from regions of interest over the heart and lungs, after three bicycle exercise tests: to maximal, 80% and 60% of predicted maximal heart rate. The initial lung uptake was lowest at peak heart rate, and increased linearly to 121% and 140% of this at 80% and 60% of predicted maximal heart rate. The three delayed lung images were identical. The myocardial activity was highest at maximal exercise, and decreased linearly with heart rate, resulting in a net fall in the sum of initial lung and myocardial activity to 93% and 86% at the two lowest exercise levels. The mean initial lung/myocardial uptake ratio was 0.44, 0.67, and 1.00 from highest to lowest heart rate, and the lung thallium-201 clearance 9%, 21% and 33%. These results suggest that the initial lung thallium-201 uptake, clearance and lung/myocardial uptake ratio are normally inversely related to cardiac output. When used as indicators of left ventricular dysfunction, interpretation should be cautious in patients performing submaximal exercise tests. The lung thallium prognostic indicators seem less specific than previously indicated.
Doppler echocardiographic assessment of the aortic valve area (AVA) using the continuity equation was performed before cardiac catheterization in 100 patients with suspected aortic stenosis. Doppler echocardiographic AVA correlated closely with AVA calculated by the Gorlin equation at catheterization (r = 0.96). However, Doppler echocardiography slightly but systematically underestimated the AVA (p less than 0.001) and did so most markedly in patients with mild stenosis (greater than 1.0 cm2). In multivariate analysis, the difference in AVA by the 2 techniques was positively associated with left ventricular (LV) stroke volume and inversely with the difference between mean catheterization and Doppler gradients, LV ejection fraction and LV outflow tract velocity. Furthermore, the AVA difference also was related to gender, being larger in women. Thus, overall Doppler echocardiography reliably assesses AVA, but the usefulness of the method is somewhat reduced by its underestimation of AVA in mild stenosis. This drawback, however, is usually overcome by taking patients' symptoms into account. Furthermore, lacking a "gold standard," this underestimation need not imply errors of the Doppler echocardiographic method alone, but also may reflect known inaccuracies of the catheterization technique.
Maximal oxygen consumption was measured during treadmill exercise in 44 patients with coronary artery disease. Exercise was performed before and after a 4-week course of training. Patients with a previous myocardial infarction and no angina pectoris (n = 27) increased their maximal oxygen consumption by 16% after training. There was no such increase in patients with angina pectoris (n = 17). The subjective feeling of wellbeing after training was the same in both groups of patients. Thus, the advantages of short term training can be both of a symptomatic character and a real improvement in cardiovascular function.
The effects of a period of 4 weeks training on treadmill exercise performance were evaluated in 27 patients, mean +/- SD age 55 +/- 7 years, who had previously suffered a myocardial infarction (17 Q-wave) 3-24 months (mean 11 +/- 8). To ensure comparability of exercise levels only patients who obtained their predicted maximal heart rate in the initial test were included. All trained 3-4 hours daily 5 days a week at an average maximal intensity of 85% of their initial peak heart rate. They performed 2 maximal exercise tests before and 1 after the training course. Maximal oxygen consumption was 28.1 +/- 5.3 and 28.8 +/- 6.5 ml/kg/minute (NS) before, and increased by 16% to 33.4 +/- 7.2 after training (P less than 0.01). Treadmill exercise distance was 510 +/- 153 and 559 +/- 163 meters (10% increase, P less than 0.01) before, and increased by 14% to 638 +/- 156 after (P less than 0.01). Heart rate, ratio of respiratory gas exchange, and breathing frequency remained unchanged in all three tests at maximal exercise, but were significantly lower at identical submaximal levels after training, while the respiratory tidal volume increased. Resting heart rate decreased by 12% after (P less than 0.01). Thus, aerobic exercise performance is improved by short-term training after myocardial infarction. By the longitudinal design of the study, and the maximal initial exercise test, this physiological improvement can be differentiated from that of increased motivation, and of increased treadmill exercise distance due to improved exercise technique.
The effects of heart rate on the myocardial uptake and clearance of 201Tl were studied prospectively in seven healthy men, mean age 43 +/- 7 (s.d.) yr. Initial and delayed (3 hr) thallium images were obtained in three views after three bicycle exercise tests: to maximal, 80% and 60% of predicted maximal heart rate. The mean of three views initial myocardial 201Tl uptake was higher at maximal than at both 80% and 60% of predicted maximal heart rate, being 81% (p less than 0.01) and 60% (p less than 0.01) of maximal activity, respectively. The myocardial activity in the delayed images was identical. There was a linear relationship between heart rate and the initial myocardial activity, r = 0.86 (p less than 0.001). The mean (range) 201Tl clearance was 58% (51-65), 47% (34-56), and 34% (22-49) (all differences p less than 0.01), respectively. Concordance among the three individual views in estimating clearance was best for the highest exercise level. There was a linear relationship between heart rate and clearance, r = 0.80 (p less than 0.001). Clearance was altered by only 1.67 x 10%/heart bpm (0.024 hr/heart beat). Clearance in the liver, spleen and lungs increased at submaximal exercise levels. Thus, a linear relationship between heart rate and clearance is the result of changes in the initial exercise myocardial 201Tl activity. Submaximal exercise may reduce reproducibility of clearance estimation, and the change of myocardial clearance with heart rate seems less than previously suggested.
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