Jens Jensen

Instantaneous Wave-free Ratio versus Fractional Flow Reserve to Guide PCI

Background The instantaneous wave‐free ratio (iFR) is an index used to assess the severity of coronary‐artery stenosis. The index has been tested against fractional flow reserve (FFR) in small trials, and the two measures have been found to have similar diagnostic accuracy. However, studies of clinical outcomes associated with the use of iFR are lacking. We aimed to evaluate whether iFR is noninferior to FFR with respect to the rate of subsequent major adverse cardiac events. Methods We conducted a multicenter, randomized, controlled, open‐label clinical trial using the Swedish Coronary Angiography and Angioplasty Registry for enrollment. A total of 2037 participants with stable angina or an acute coronary syndrome who had an indication for physiologically guided assessment of coronary‐artery stenosis were randomly assigned to undergo revascularization guided by either iFR or FFR. The primary end point was the rate of a composite of death from any cause, nonfatal myocardial infarction, or unplanned revascularization within 12 months after the procedure. Results A primary end‐point event occurred in 68 of 1012 patients (6.7%) in the iFR group and in 61 of 1007 (6.1%) in the FFR group (difference in event rates, 0.7 percentage points; 95% confidence interval [CI], ‐1.5 to 2.8; P=0.007 for noninferiority; hazard ratio, 1.12; 95% CI, 0.79 to 1.58; P=0.53); the upper limit of the 95% confidence interval for the difference in event rates fell within the prespecified noninferiority margin of 3.2 percentage points. The results were similar among major subgroups. The rates of myocardial infarction, target‐lesion revascularization, restenosis, and stent thrombosis did not differ significantly between the two groups. A significantly higher proportion of patients in the FFR group than in the iFR group reported chest discomfort during the procedure. Conclusions Among patients with stable angina or an acute coronary syndrome, an iFR‐guided revascularization strategy was noninferior to an FFR‐guided revascularization strategy with respect to the rate of major adverse cardiac events at 12 months. (Funded by Philips Volcano; iFR SWEDEHEART ClinicalTrials.gov number, NCT02166736.)

Bivalirudin versus Heparin Monotherapy in Myocardial Infarction

BACKGROUND The comparative efficacy of various anticoagulation strategies has not been clearly established in patients with acute myocardial infarction who are undergoing percutaneous coronary intervention (PCI) according to current practice, which includes the use of radial‐artery access for PCI and administration of potent P2Y12 inhibitors without the planned use of glycoprotein IIb/IIIa inhibitors. METHODS In this multicenter, randomized, registry‐based, open‐label clinical trial, we enrolled patients with either ST‐segment elevation myocardial infarction (STEMI) or non‐STEMI (NSTEMI) who were undergoing PCI and receiving treatment with a potent P2Y12 inhibitor (ticagrelor, prasugrel, or cangrelor) without the planned use of glycoprotein IIb/IIIa inhibitors. The patients were randomly assigned to receive bivalirudin or heparin during PCI, which was performed predominantly with the use of radial‐artery access. The primary end point was a composite of death from any cause, myocardial infarction, or major bleeding during 180 days of follow‐up. RESULTS A total of 6006 patients (3005 with STEMI and 3001 with NSTEMI) were enrolled in the trial. At 180 days, a primary end‐point event had occurred in 12.3% of the patients (369 of 3004) in the bivalirudin group and in 12.8% (383 of 3002) in the heparin group (hazard ratio, 0.96; 95% confidence interval [CI], 0.83 to 1.10; P=0.54). The results were consistent between patients with STEMI and those with NSTEMI and across other major subgroups. Myocardial infarction occurred in 2.0% of the patients in the bivalirudin group and in 2.4% in the heparin group (hazard ratio, 0.84; 95% CI, 0.60 to 1.19; P=0.33), major bleeding in 8.6% and 8.6%, respectively (hazard ratio, 1.00; 95% CI, 0.84 to 1.19; P=0.98), definite stent thrombosis in 0.4% and 0.7%, respectively (hazard ratio, 0.54; 95% CI, 0.27 to 1.10; P=0.09), and death in 2.9% and 2.8%, respectively (hazard ratio, 1.05; 95% CI, 0.78 to 1.41; P=0.76). CONCLUSIONS Among patients undergoing PCI for myocardial infarction, the rate of the composite of death from any cause, myocardial infarction, or major bleeding was not lower among those who received bivalirudin than among those who received heparin monotherapy. (Funded by the Swedish Heart–Lung Foundation and others; VALIDATE‐SWEDEHEART ClinicalTrialsRegister.eu number, 2012–005260–10; ClinicalTrials.gov number, NCT02311231.)

Analgesic effects of adenosine during exercise-provoked myocardial ischaemia

The analgesic potential of adenosine during myocardial ischaemia was studied in patients with coronary artery disease and exercise-limiting angina pectoris. Patients were given a low dose of adenosine or placebo in a double-blind cross-over fashion by continuous i.v. infusion before and during two exercise tests. Adenosine decreased chest pain by 45 +/- 13% (p < 0.02) while heart rate-blood pressure product and electrocardiographic signs of myocardial ischaemia did not change. Ten healthy volunteers received increasing doses of adenosine by continuous i.v. infusion. The heat pain threshold increased in skin covering the chest (p < 0.03) and also tended to increase at the left thenar eminence (p < 0.07). In conclusion, the neuromodulator adenosine can therefore act as an analgesic in myocardial ischaemia.

Intravascular Ultrasound Guidance is Associated with Better Outcome in Patients Undergoing Unprotected Left Main Coronary Artery Stenting Compared with Angiography Guidance Alone

Background— Small observational studies have indicated better outcome with intravascular ultrasound (IVUS) guidance when performing unprotected left main coronary artery (LMCA) percutaneous coronary intervention (PCI), but the overall picture remains inconclusive and warrants further investigation. We studied the impact of IVUS guidance on outcome in patients undergoing unprotected LMCA PCI in a Swedish nationwide observational study. Methods and Results— Patients who underwent unprotected LMCA PCI between 2005 and 2014 because of stable coronary artery disease or acute coronary syndrome were included from the nationwide SCAAR (Swedish Coronary Angiography and Angioplasty Registry). Of 2468 patients, IVUS guidance was used in 621 (25.2%). The IVUS group was younger (median age, 70 versus 75 years) and had fewer comorbidities but more complex lesions. IVUS was associated with larger stent diameters (median, 4 mm versus 3.5 mm). After adjusting for potential confounders, IVUS was associated with significantly lower occurrence of the primary composite end point of all-cause mortality, restenosis, or definite stent thrombosis (hazard ratio, 0.65; 95% confidence interval, 0.50–0.84) and all-cause mortality alone (hazard ratio, 0.62; 95% confidence interval, 0.47–0.82). In 340 propensity score–matched pairs, IVUS was also associated with significantly lower occurrence of the primary end point (hazard ratio, 0.54; 95% confidence interval, 0.37–0.80). Conclusions— IVUS was associated with an independent and significant outcome benefit when performing unprotected LMCA PCI. Potential mediators of this benefit include larger and more appropriately sized stents, perhaps translating into lower risk of subsequent stent thrombosis. Although residual confounding cannot be ruled out, our findings indicate a possible hazard when performing unprotected LMCA PCI without IVUS guidance.

On-line vectorcardiography during elective coronary angioplasty indicates procedure-related myocardial infarction.

BackgroundIncreased creatine kinase concentrations after elective percutaneous transluminal coronary angioplasty (PTCA) have been shown to be associated with increased late cardiac mortality. ObjectiveTo evaluate the potential of continuous on‐line vectorcardiography during elective PTCA to identify procedure‐related myocardial infarction. MethodsPatients (n  = 192, ages 58 ± 10 years), treated with elective and initially successful PTCA, were studied using vectorcardiogram (VCG) recordings. VCG monitoring was started 5 min before start of the PTCA and was carried out during the entire procedure, for at least 30 min after the first balloon inflation. ST‐segment vector magnitude (ST‐VM) and ST‐segment change vector magnitude (STC‐VM) were monitored. ResultsFifteen (7.8%) procedure‐related myocardial infarctions occurred. Indicators of procedure‐related myocardial infarction were maximum value of ST‐VM (P  < 0.001) and STC‐VM (P  < 0.001), total ischemic time of all ST‐VM episodes (P  < 0.001) and STC‐VM episodes (P  < 0.001). The variable most closely related to a procedure‐related myocardial infarction was the maximum STC‐VM value during the procedure. With an optimized cutoff value, maximum STC‐VM predicts a procedure‐related myocardial infarction with a sensitivity of 93%, a specificity of 59% and a negative predictive value of 99%. Patients who had a stent implanted had significantly greater VCG values (P  < 0.05–P  < 0.001) than the group without a stent. There was a trend (P  < 0.06) to a relation between increased creatine kinase concentration and stent implantation. In patients both with and without an implanted stent, greater STC‐VM values were associated with procedure‐related myocardial infarction (P  < 0.01). ConclusionContinuous VCG monitoring during elective PTCA is a promising method for immediate detection of patients at increased risk of procedure‐related myocardial infarction.

Technical Skills Assessment in a Coronary Angiography Simulator for Construct Validation.

Introduction The aim of this study was to evaluate technical skills in a coronary angiography (CA) simulator to establish the performance level of trainees and experts in virtual CA. The traditional master-apprentice way of learning CA is by practicing on patients despite a known risk for complications during training. Safe CA training is warranted, and simulators might be one possibility. Simulators used must be validated regarding their ability to separate trainees from experts. Construct validation of a CA simulator, to our knowledge, has not yet been published. Methods Ten cardiology residents without experience in CA, 4 intermediate, and 10 CA experts performed 5 CAs in the Mentice VIST (Vascular Intervention Simulation Trainer). Metrics reflecting proficiency skills such as total procedure time, fluoroscopy time, and contrast volume were extracted from the simulator computer and compared between the groups. All examinations were videotaped, and the number of handling errors was examined. The videos were evaluated by 2 experts blinded to the test object’s performance level. Results Experts outperformed trainees in all metrics measured by the simulator. Improvement was demonstrated in all metrics through all 5 CAs. Furthermore, beginners had more handling errors compared with experts. Conclusions Mentice VIST simulator can distinguish between trainees and experts in CA in the metrics extracted from the computer and therefore prove the concept of construct validity.

The use of fluoroscopy to construct learning curves for coronary angiography

Objectives: The aim of this study was to assess learning curves for coronary angiography using registry data from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR). Background: ACC and ESC guidelines for cardiologists in training recommend 200–300 coronary angiographies as primary operator. Whether this is safe or sufficient to reach an adequate proficiency level is not known. The development of learning curves and factors that can determine progress is not yet clearly stated. Methods: We extracted data from SCAAR 2005–2009 and identified 20 novel and 21 expert operators in coronary angiography during this observation period. Metrics possibly influenced by proficiency level were compared between the two groups. Learning curves were then identified with the experts performance as reference defined as interquartile range (IQR). Results: Data from a total of 24,000 coronary angiographies were examined. Beginners used similar volumes of contrast but had longer fluoroscopy time compared with experts. Fluoroscopy time appeared to be a metric that demonstrated a clear learning curve and beginners reached experts IQR in 50 % (median) of the procedures after ∼140 coronary angiographies. The risk of complications was independently associated with fluoroscopy time. Conclusions: Fluoroscopy time seems to be the best metric to determine coronary angiography performance level and might therefore be a good proficiency measure during training. On the basis of our results we recommend the trainee to perform at least 150 coronary angiographies during supervision before proceeding with unsupervised procedures. It is not clear if the suggested number of procedures will result in decreased number of complications but the data suggests that fluoroscopy time might be a surrogate marker for complications.

Prognostic Value of Ischemia Monitoring with On-Line Vectorcardiography in Patients with Unstable Coronary Artery Disease

Aim: The aim of this study was to determine whether on-line vectorcardiography (VCG) gives independent prognostic information, regarding death, myocardial infarction (MI), and revascularization in patients with unstable coronary artery disease, i.e. unstable angina or non-Q-wave MI. Methods and Results: One hundred and fifty patients (mean age 69 ± 10), participating in a randomized study of low-molecular-weight heparin in unstable coronary artery disease, were studied with on-line VCG recordings for 24 h. During a 5–6-month follow-up, 11 patients died, 14 suffered a nonfatal MI and 31 were revascularized. Univariate predictors of death were diabetes mellitus (p < 0.01), maximum ST vector magnitude (ST-VM; p < 0.001), maximum ST change vector magnitude (STC-VM; p < 0.001), number of ST-VM (p < 0.01) and STC-VM episodes (p < 0.001). In multivariate analysis, the number of STC-VM episodes (p < 0.01) and diabetes mellitus (p < 0.02) each gave independent prognostic information regarding death. When all cardiovascular events were combined, the inhability to perform an exercise test (p < 0.05), maximum value of ST-VM (p < 0.01) and STC-VM (p < 0.001), the number of episodes of STC-VM (p < 0.001) and ST-VM (p < 0.001) all gave prognostic information. In multivariate analysis, the inability to perform an exercise test and the number of STC-VM episodes were independent predictors. Conclusion: VCG monitoring during the first 24 h of hospitalization for unstable coronary artery disease gives independent prognostic information.

Prognostic Role of On-Line Vectorcardiography as Regards Repeat Revascularization after Successful Coronary Angioplasty

This study evaluated the prognostic significance of continuous on-line vectorcardiography (VCG) during elective coronary angioplasty (percutaneous transluminal coronary angioplasty, PTCA). Patients (n = 192, mean age 58 ± 10), treated with elective and initially successful PTCA, were included. VCG monitoring was started before start of the PTCA procedure and was carried out during the entire procedure. ST vector magnitude (ST-VM) was monitored. A 6-month follow-up was obtained. Main outcome measures were the frequency of cardiac events and revascularization during follow-up. During follow-up, 1 patient died, 6 suffered a nonfatal myocardial infarction and 50 were revascularized. Angiography revealed restenosis in 88% of the patients who had a revascularization. In the total patient group, the VCG predictor of revascularization was the total ischemic time of all ST-VM episodes (p = 0.05). Clinical predictors of revascularization were diabetes mellitus (p < 0.01), a more severe type of lesion (type B; p < 0.01), percent post-PTCA stenosis (p < 0.05), nominal balloon size (p < 0.01), maximum balloon pressure (p < 0.05) and no stent implanted (p < 0.001). In a multivariate analysis all the above significant univariate variables of revascularization were entered. Total ischemic time of ST-VM (p < 0.01) was the best variable giving independent prognostic information. In the nonstent group, total ischemic time of ST-VM (p < 0.01) was the only independent predictor of a further revascularization. In conclusion, VCG monitoring during elective PTCA gives on-line information that identifies patients at an increased risk of a revascularization during 6 months after the initial procedure.

Ischemia monitoring with on-line vectorcardiography compared with results from a predischarge exercise test in patients with acute ischemic heart disease

Information from 24-hour monitoring with on-line vectorcardiography, starting immediately after admission, was compared with results from a predischarge exercise test 3-13 days after admission. A total of 169 patients with acute myocardial infarction and 73 patients with unstable angina pectoris were investigated. Patients were followed for 487 +/- 135 days. During the follow-up period, 19 patients (8%) died from cardiac causes and 34 (14%) were hospitalized for a myocardial infarction. The QRS vector difference (QRS-VD), ST change vector magnitude (STC-VM), ST vector magnitude (ST-VM), and ST vector leads X, Y, Z were monitored. Patients with ST depression on the exercise test showed higher occurrence of transient, supposedly ischemic, episodes of QRS-VD, STC-VM, and ST-VM than patients without ST depression. The sensitivity and specificity of identifying patients with ST depression at the exercise test were respectively, 71 and 47% for QRS-VD episodes, 58 and 56% for ST-VM episodes, and 55 and 65% for STC-VM episodes. The maximum ST depression at the exercise test was related to the maximum ST depression in vector lead X (r = .44, P < .001) and the number of STC-VM (r = .40, P < .001), ST-VM (r = .37, P < .001), and QRS-VD (r = .33, P < .001) episodes on the VCG. In multivariate analysis, maximum ST depression in vector lead X and STC-VM episodes were the best determinants for ST depression at the exercise test. In a Cox regression model, the optimal combination of exercise test data in patients who died from cardiac causes exhibited a global chi-square value of 20.0. The combination of these data and the number of STC-VM episodes increased the global chi-square value to 30.6. This study indicates that in patients with acute ischemic heart disease, early continuous vectorcardiographic monitoring may predict the results from a predischarge exercise test and also contributes independent prognostic information beyond that of exercise test data.