Tage Nilsson

Long-term safety and efficacy of drug-eluting versus bare-metal stents in Sweden.

BACKGROUND The long-term safety and efficacy of drug-eluting coronary stents have been questioned. METHODS We evaluated 47,967 patients in Sweden who received a coronary stent and were entered into the Swedish Coronary Angiography and Angioplasty Registry between 2003 and 2006 and for whom complete follow-up data were available for 1 to 5 years (mean, 2.7). In the primary analysis, we compared patients who received one drug-eluting coronary stent (10,294 patients) with those who received one bare-metal stent (18,659), after adjustment for differences in clinical characteristics of the patients and characteristics of the vessels and lesions. RESULTS Analyses of outcome were based on 2380 deaths and 3198 myocardial infarctions. There was no overall difference between the group that received drug-eluting stents and the group that received bare-metal stents in the combined end point of death or myocardial infarction (relative risk with drug-eluting stents, 0.96; 95% confidence interval [CI], 0.89 to 1.03) or the individual end points of death (relative risk, 0.94; 95% CI, 0.85 to 1.05) and myocardial infarction (relative risk, 0.97; 95% CI, 0.88 to 1.06), and there was no significant difference in outcome among subgroups stratified according to the indication for stent implantation. Patients who received drug-eluting stents in 2003 had a significantly higher rate of late events than patients who received bare-metal stents in the same year, but we did not observe any difference in outcome among patients treated in later years. The average rate of restenosis during the first year was 3.0 events per 100 patient-years with drug-eluting stents versus 4.7 with bare-metal stents (adjusted relative risk, 0.43; 95% CI, 0.36 to 0.52); 39 patients would need to be treated with drug-eluting stents to prevent one case of restenosis. Among high-risk patients, the adjusted risk of restenosis was 74% lower with drug-eluting stents than with bare-metal stents, and only 10 lesions would need to be treated to prevent one case of restenosis. CONCLUSIONS As compared with bare-metal stents, drug-eluting stents are associated with a similar long-term incidence of death or myocardial infarction and provide a clinically important decrease in the rate of restenosis among high-risk patients.

Potential of Carotid Ultrasonography in the Diagnosis of Coronary Artery Disease A Comparison With Exercise Test and Variance ECG

BACKGROUND AND PURPOSE Carotid artery atherosclerosis has been shown to correlate with coronary artery disease (CAD). This study evaluates the capacity of duplex ultrasonography of the carotid arteries as a tool in the diagnosis of CAD in comparison with exercise stress test and variance ECG. METHODS Carotid ultrasonography, exercise stress test, and variance ECG were performed in 184 symptomatic patients evaluated with coronary angiography. The diagnostic capacity of the studied noninvasive methods was assessed by use of receiver operating characteristic (ROC) curves constructed by successive consideration of several cut points, such as (1) the presence of unilateral/bilateral plaques and (2) cross-sectional common carotid artery (CCA) intima-media (IM) area from 10 to 30 mm2 for ultrasonography; (1) ST depression > or =0.1 mV and > or =0.2 mV with and (2) without chest pain for exercise test; and electrical variability index from 50 to 100 for variance ECG. RESULTS Coronary angiography revealed the presence of CAD (> or =50% luminal stenosis in 1 or more major epicardial arteries) in 147 patients (80%). Identification of carotid plaques on one or both sides and calculation of the left-sided (but not right-sided) CCA IM area provided a significant discrimination (P<.001 and P<.01, respectively) of patients with CAD. The discriminating capacity of the ultrasound procedures was equal to that of variance ECG and exercise test with ST depression criterion only but somewhat lower than that of exercise test with the combined chest pain and ST depression criterion (P<.05). However, at the chosen cut points, carotid plaque identification offered higher sensitivity than exercise test with either criterion (P<.01 and P<.001, respectively). CONCLUSIONS Carotid ultrasonography is a useful diagnostic method that is comparable to exercise test and variance ECG for detection of CAD in a high-prevalence population.

Safety and efficacy of drug-eluting vs. bare metal stents in patients with diabetes mellitus: long-term follow-up in the Swedish Coronary Angiography and Angioplasty Registry (SCAAR).

AIMS Patients with diabetes mellitus have more extensive coronary artery disease, more disease progression, and restenosis. The use of drug-eluting stents (DES) in these patients is widespread, despite uncertain long-term safety and efficacy. METHODS AND RESULTS All consecutive patients with diabetes mellitus in Sweden who underwent percutaneous coronary intervention were entered into the Swedish Coronary Angiography and Angioplasty Registry (SCAAR) during 2003-06 with complete follow-up for 1-4 years (median 2.5). Patients who received at least one DES (n = 4754) were compared with those who received only bare metal stents (BMS) (n = 4956) at the index procedure. Combined outcome of death or myocardial infarction (MI) showed no difference for DES vs. BMS, relative risk (RR), 0.91 [95% confidence interval (CI), 0.77-1.06]. Myocardial infarction was significantly less common with DES in patients who received only one stent RR, 0.80 (95% CI, 0.66-0.96). The restenosis rate was 50% lower in DES-treated patients RR, 0.50 (95% CI, 0.35-0.70) and was associated with a higher adjusted RR of MI, RR, 5.03 (95% CI, 4.25-5.97). DES was associated with reduced restenosis rates in all subgroups of diabetic patients with the greatest benefit in stent diameters <3 mm or stent length >20 mm. The number of lesions treated with DES to prevent one restenosis ranged from 11 to 47 in various subgroups. CONCLUSION This real-life registry study shows that restenosis was halved by DES in diabetic patients with stable or unstable coronary disease, with similar risk of death or MI up to 4 years compared with BMS.

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.

Incidence of asthma among workers exposed to sulphur dioxide and other irritant gases

The aim of the present study was to investigate whether repeated peak exposure (gassings) to sulphur dioxide (SO2) and other irritant gases increases the risk of new-onset asthma. A questionnaire was sent to 4,112 sulphite workers, of whom 1,919 completed the questionnaire and 396 completed the short-form questionnaire, which was sent out as a last reminder. A sample of 130 nonrespondents completed a telephone interview using the short-form questionnaire. The incidence of adult-onset, physician-diagnosed asthma during employment duration was analysed in relation to exposure to SO2 and gassings giving rise to respiratory symptoms. Incidence rates, as well as incidence rate ratios with 95% confidence interval (CI), were calculated. Further Cox regression models were used allowing assessment of hazard ratios (HR) stratified for sex and adjusted for atopy, smoking habits and age. The incidence rate for asthma among sulphite mill workers reporting gassings of SO2 was 6.2 out of 1,000 person-yrs, compared with 1.9 out of 1,000 person-yrs among subjects unexposed to SO2 and any gassings (HR (95% CI) 4.0 (2.1–7.7)). Among males reporting gassings to SO2, the HR (95% CI) for asthma was 5.8 (2.6–13) compared with unexposed males. In conclusion, repeated peak exposure to sulphur dioxide increased the incidence of asthma during work in sulphite pulp mills, which supports the hypothesis of irritant-induced asthma.

Outcome of drug-eluting versus bare-metal stenting used according to on- and off-label criteria

OBJECTIVES The aim of this study was to investigate the outcome of bare-metal stents (BMS) versus drug-eluting stents (DES) after on-label as well as off-label use. BACKGROUND DES lower restenosis rates while not influencing the risk for death and myocardial infarction when used in Federal Food and Drug Administration (FDA)-approved indications. It is debated whether the clinical results of this so-called on-label use might be extrapolated to off-label situations. METHODS The SCAAR (Swedish Coronary Angiography and Angioplasty Registry) was used to investigate the outcomes in 17,198 patients who underwent stenting with an on-label indication (10,431 BMS and 6,767 DES patients) and 16,355 patients in the context of an off-label indication (9,907 BMS and 6,448 DES patients). The patients were included from 2003 to 2005 with a minimum follow-up of 1 year and a maximum of 4 years. The analysis was adjusted for differences in baseline characteristics. RESULTS There were not significant differences between on-label DES and BMS (adjusted hazard ratio: 1.02; 95% confidence interval: 0.92 to 1.13) or between off-label DES and BMS (adjusted hazard ratio: 0.95; 95% confidence interval: 0.87 to 1.04) use with regard to the incidence of myocardial infarction and death. Off-label use of DES did not lead to significant differences in the combined risk of death and myocardial infarction compared with BMS throughout the whole spectrum of clinical indications. CONCLUSIONS In contemporary Swedish practice, neither on- nor off-label use of DES is associated with worse outcome than use of BMS.

Initial clinical experience with an everolimus eluting platinum chromium stent (Promus Element) in unselected patients from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR)

BACKGROUND The safety and efficacy of the Promus Element stent have been recently demonstrated in a selected population from one randomized trial. The aim of this study was to describe the initial clinical experience with the everolimus eluting platinum chromium stent (Promus Element) in unselected patients from a real life nationwide registry. METHODS The Promus Element DES was compared to all other DES implanted in Sweden (with more than 500 implants) from November 2009 to March 2011. The results were assessed using Cox regression. RESULTS A total of 13,577 stents (Promus Element, n=2724, Cypher, n=782; Endeavor, n=747; Taxus Liberté, n=1393, Xience V/Promus, n=4832, Resolute, n=1566, Xience Prime, n=4832) were implanted at 8375 procedures. At one year the restenosis rate in the Promus Element was not significantly different from the overall DES group (2.8% vs. 2.7%, adjusted HR:1.17, 95% CI: 0.75-1.75). A significantly lower restenosis rate was observed in the Promus Element when compared with Endeavor (2.8% vs. 5.8%; adjusted HR: 0.44; 95% CI: 0.26-0.74). The stent thrombosis (ST) rate at one year was not significantly different in the Promus Element as compared with the overall DES group (0.2% vs. 0.5% adjusted HR: 0.59; 95% CI: 025-1.40). ST rate was significantly lower as compared with Endeavor stent (0.2% vs. 0.8%; HR: 0.24; 95% CI: 0.08-0.67). CONCLUSIONS In a large unselected population the Promus Element stent appears to be safe and effective with a low risk of restenosis and ST.

Impact on image quality and radiation exposure in coronary CT angiography: 100 kVp versus 120 kVp

Background: The risk of radiation-induced cancer has become a major concern with the increasing use of computed tomography (CT). Purpose: To compare image quality and radiation doses when decreasing X-ray tube peak kilovoltage (kVp) from 120 to 100 kVp in patients undergoing coronary CT angiography (CCTA). Material and Methods: Patients referred for evaluation of suspected coronary artery disease (CAD) underwent 64-channel detector CCTA using a tube voltage of either 120 kVp (n = 46) or 100 kVp (n = 82). The individual volume CT dose index (CTDIvol) and dose length product (DLP) were recorded and effective radiation dose was estimated on the basis of DLP. Subjective image quality was assessed by two radiologists on per-patient based consensus. Vascular density and image noise were quantified in the left main coronary artery (LMCA) and proximal ascending aorta (AA). Mean density in the adjacent perivascular tissue was also quantified. Contrast-to-noise ratio (CNR) was calculated. Corresponding invasive coronary angiography (ICA) was performed, which constituted the gold standard. Results: Mean values in the 100/120 kVp cohorts regarding CNR in the LMCA were 12.7/16.0 (P<0.0001)) and in the AA 13.2/17.2 (P<0.0001), CTDIvol 34.4/57.4 mGy (a 40% reduction, P<0.0001), DLP 578/1125 mGy × cm (P<0.0001), and estimated effective dose 9.6/20.2 mSv (P<0.0001). There was no statistically significant difference in subjective image quality between the two cohorts. The sensitivity to detect significant coronary stenoses was 88% (120 kVp) and 84% (100 kVp) and the specificity was 71% (120 kVp) and 74% (100 kVp), respectively. Conclusion: By reduction of tube voltage from 120 to 100 kVp at CCTA, while keeping all other scanning parameters unchanged, the radiation dose to the patient can be almost halved while keeping the diagnostic image quality at a clinically acceptable level.

A comparison of spiral computed tomography and latex agglutination D-dimer assay in acute pulmonary embolism using pulmonary arteriography as gold standard.

Objective : To compare the diagnostic accuracy of contrast medium enhanced spiral computed tomography of the pulmonary arteries (s-CTPA) and a latex agglutination D-dimer assay in patients with suspected acute pulmonary embolism (PE) by using pulmonary arteriography (PA) and clinical follow-up as reference method. Design : Ninety hemodynamically stable patients with symptoms of acute pulmonary embolism were prospectively evaluated with s-CTPA and pulmonary arteriography (PA) within 24 h from admission. Plasma D-dimer levels on admittance were analyzed using a rapid latex agglutination D-dimer assay. The outcome of D-dimer concentrations in plasma below 0.25 and 0.5 mg/l was studied. Results : All PA and s-CTPA investigations were regarded as of acceptable diagnostic quality in a consensus reading. Thirty-three patients had a positive PA (37%). Three patients had false negative and two patients had false positive s-CTPA findings. s-CTPA had 91% sensitivity, 96% specificity, 94% positive predictive value (PPV) and 95% negative predictive value (NPV). The sensitivity and specificity for D-dimer below 0.5 mg/l were 79 and 88%, respectively. The PPV and NPV were 81 and 87%. If a cut-off level of 0.25 mg/l was used the corresponding figures were 91, 65, 63 and 92%. Conclusion : s-CTPA has a higher sensitivity and specificity than latex agglutination D-dimer. A cut-off level of 0.25 mg/l can be used as screening method, but s-CTPA must be performed to exclude false positive cases.

Geographical differences in the incidence of acute myocardial infarction in Sweden. Analyses of possible causes using two parallel case–control studies

Abstract. Hammar N, Andersson T, Reuterwall C, Nilsson T, Knutsson A, Hallqvist J, Ahlbom A (Karolinska Institutet, Stockholm; Stockholm, Center for Public Health; Västernorrland County Council, Sundsvall; and Norrland University Hospital, Umeå, Sweden). Geographical differences in the incidence of acute myocardial infarction in Sweden. Analyses of possible causes using two parallel case–control studies. J Intern Med 2001; 249: 137–144.