Coronary artery dominance and the risk of adverse clinical events following percutaneous coronary intervention: insights from the prospective, randomised TWENTE trial.

AIMS: To investigate the prognostic value of coronary dominance for various adverse clinical events following the implantation of drug-eluting stents. METHODS AND RESULTS: We assessed two-year follow-up data of 1,387 patients from the randomised TWENTE trial. Based on the origin of the posterior descending coronary artery, coronary circulation was categorised into left and non-left dominance (i.e., right and balanced). Target vessel-related myocardial infarction (MI) was defined according to the updated Academic Research Consortium (ARC) definition (2x upper reference limit of creatine kinase [CK], confirmed by CK-MB elevation), and periprocedural MI (PMI) as MI ≤48 hours following PCI. One hundred and thirty-six patients (9.8%) had left and 1,251 (90.2%) non-left dominance. Target lesions were more frequently located in dominant arteries (p<0.005). Left dominance was associated with more severe calcifications (p=0.006) and more bifurcation lesions (p=0.031). Non-left dominance tended to be less frequent in men (p=0.09). Left coronary dominance was associated with more target vessel-related MI (14 [10.3%] vs. 62 [5.0%], p=0.009). Left dominance independently predicted PMI (adjusted HR 2.19, 95% CI: 1.15-4.15, p=0.017), while no difference in other clinical endpoints was observed between dominance groups. CONCLUSIONS: In the population of the TWENTE trial, we observed a higher incidence of periprocedural myocardial infarction in patients who had left coronary dominance.

Clinical outcome following second-generation drug-eluting stent use for off-label versus on-label indications: insights from the two-year outcome of the TWENTE trial.

AIMS: Drug-eluting stents (DES) were first used on-label - in simple patients with low clinical risk and easily accessible lesions. Currently, DES are increasingly used off-label - in complex patients undergoing percutaneous coronary interventions (PCI) with historically higher event risk. Therefore, our aim was to investigate whether patients with off-label indications for DES use had similar outcomes compared to patients who were treated for on-label indications only. We analysed two-year follow-up data of 1,387 TWENTE trial patients, treated with second-generation everolimus-eluting XIENCE V or zotarolimus-eluting Resolute stents, and compared off-label vs. on-label DES use with regard to the following clinical endpoints: cardiac death, myocardial infarction (MI), periprocedural MI (≤48 hrs), and target vessel revascularisation (TVR). Patients with off-label DES use (n=1,033; 74.5%) had more diabetes (22.9% vs. 17.5%; p=0.032), previous MI (35.9% vs. 22.3%; p<0.001), type B2/C lesions (84.7% vs. 62.7%; p<0.001), and acute coronary syndromes (57.8% vs. 33.3%; p<0.001). Nevertheless, cardiac death and TVR rates were similar to those of patients with on-label DES use (p>0.8). Following off-label DES use, there was a higher incidence of PMI (5.0% vs. 1.4%; p=0.003), of which only 1.1% reached creatine kinase levels >5x the upper limit of normal (ULN). Despite differences in risk profile, patients with off-label DES use did not differ from patients with on-label DES use in clinical endpoints other than periprocedural MI. These largely positive findings underline the favourable safety profile of second-generation DES.

Third-generation zotarolimus-eluting and everolimus-eluting stents in all-comer patients requiring a percutaneous coronary intervention (DUTCH PEERS): a randomised, single-blind, multicentre, non-inferiority trial.

BACKGROUND: Third-generation, permanent-polymer-based drug-eluting stents with novel, flexible designs might be more easily delivered than previous generations of stents in complex coronary lesions, but might be less longitudinally stable. We aimed to assess the safety and efficacy in all-comer patients of two third-generation stents that are often used clinically, but that have not yet been compared, and one of which has not previously been assessed in a randomised trial. METHODS: In this investigator-initiated, single-blind, multicentre, randomised, two-arm, non-inferiority trial, patients aged 18 years and older who required a percutaneous coronary intervention with implantation of a drug-eluting stent were recruited from four study sites in the Netherlands. We randomly assigned patients by independently managed computer-generated allocation sequences in a 1:1 ratio to receive either cobalt-chromium-based zotarolimus-eluting stents (Resolute Integrity, Medtronic, Santa Rosa, CA, USA) or platinum-chromium-based everolimus-eluting stents (Promus Element, Boston Scientific, Natick, MA, USA). Patients and analysts were masked to the allocated stent, but treating clinicians were not. The primary endpoint of target-vessel failure was a composite of safety (cardiac death or target-vessel-related myocardial infarction) and efficacy (target-vessel revascularisation) at 12 months, analysed by intention to treat (with a non-inferiority margin of 3·6%). This trial is registered with ClinicalTrials.gov, number NCT01331707. FINDINGS: Between Nov 25, 2010, and May 24, 2012, 1811 eligible all-comer patients, with 2371 target lesions, were enrolled in the study. 370 (20%) patients presented with ST-elevation myocardial infarction and 447 (25%) with non-ST-elevation myocardial infarction. 906 patients were assigned to receive zotarolimus-eluting stents and 905 to receive everolimus-eluting stents. Ease of stent delivery was shown by very low numbers of patients requiring treatment other than their assigned study treatment (six [1%] in the zotarolimus-eluting stent group vs five [1%] in the everolimus-eluting stent group; p=0·22). 12-month follow-up results were available for 1810 patients (one patient in the zotarolimus-eluting stent group withdrew consent). The primary endpoint was met by 55 (6%) of 905 patients in the zotarolimus-eluting stent group and 47 (5%) of 905 in the everolimus-eluting stent group. The zotarolimus-eluting stent was non-inferior to the everolimus-eluting stent (absolute risk difference 0·88%, 95% CI -1·24% to 3·01%; upper limit of one-sided 95% CI 2·69%; non-inferiority p=0·006). We noted no significant between-group differences in individual components of the primary endpoint. Definite stent thrombosis occurred in three (0·3%) patients in the zotarolimus-eluting stent group and six (0·7%) patients in the everolimus-eluting stent group (p=0·34). Longitudinal stent deformation was seen only in the everolimus-eluting stent group (nine [1·0%] of 905 vs 0 of 906, p=0·002; nine of 1591 [0·6%] everolimus-eluting stents implanted became deformed), but was not associated with any adverse events. INTERPRETATION: Both stents were similarly efficacious and safe, and provided excellent clinical outcomes, especially in view of the large number of patients who presented with acute myocardial infarctions. FUNDING: Boston Scientific, Medtronic.

Clinical outcome following stringent discontinuation of dual antiplatelet therapy after 12 months in real-world patients treated with second-generation zotarolimus-eluting resolute and everolimus-eluting Xience V stents: 2-year follow-up of the randomized TWENTE trial.

OBJECTIVES: The aim of this study was to assess the safety and efficacy of the implantation of Resolute zotarolimus-eluting stents (ZES) (Medtronic Inc., Santa Rosa, California) and Xience V everolimus-eluting stents (EES) (Abbott Vascular, Santa Clara, California) following strict discontinuation of dual antiplatelet therapy (DAPT) after 12 months. BACKGROUND: Only limited long-term follow-up data are available from head-to-head comparisons of second-generation drug-eluting stents. METHODS: The randomized TWENTE (The Real-World Endeavor Resolute Versus Xience V Drug-Eluting Stent Study in Twente) trial is an investigator-initiated study performed in a population with many complex patients and lesions and only limited exclusion criteria. Patients were randomly assigned 1:1 to ZES (n = 697) or EES (n = 694). RESULTS: Two-year follow-up information was available on all patients. The rate of continuation of DAPT beyond 12 months was very low (5.4%). The primary endpoint of target vessel failure, a composite of cardiac death, target vessel-related myocardial infarction, and target vessel revascularization, did not differ between ZES and EES (10.8% vs. 11.6, p = 0.65), despite fewer target lesion revascularizations in patients with EES (2.6% vs. 4.9%, p = 0.03). The patient-oriented composite endpoint was similar (16.4% vs. 17.1%, p = 0.75). Two-year rates of definite or probable stent thrombosis were 1.2% and 1.4%, respectively (p = 0.63). Very late definite or probable stent thrombosis occurred only in 2 patients in each study arm (0.3% vs. 0.3%, p = 1.00). CONCLUSIONS: After 2 years of follow-up and stringent discontinuation of DAPT beyond 12 months, Resolute ZES and Xience V EES showed similar results in terms of safety and efficacy for treating patients with a majority of complex lesions and off-label indications for drug-eluting stents. (The Real-World Endeavor Resolute Versus Xience V Drug-Eluting Stent Study in Twente [TWENTE]; NCT01066650).

Comparison of frequency of periprocedural myocardial infarction in patients with and without diabetes mellitus to those with previously unknown but elevated glycated hemoglobin levels (from the TWENTE Trial).

In patients without a history of diabetes mellitus, increased levels of glycated hemoglobin (HbA1c) are associated with higher cardiovascular risk. The relation between undetected diabetes and clinical outcome after percutaneous coronary intervention is unknown. To investigate whether these patients may have an increased risk of periprocedural myocardial infarction (PMI), the most frequent adverse event after percutaneous coronary intervention, we assessed patients of the TWENTE trial (a randomized, controlled, second-generation drug-eluting stent trial) in whom HbA1c data were available. Patients were classified as known diabetics or patients without a history of diabetes who were subdivided into undetected diabetics (HbA1c ≥6.5%) and nondiabetics (HbA1c <6.5%). Systematic measurement of cardiac biomarkers and electrocardiographic assessment were performed. One-year clinical outcome was also compared. Of 626 patients, 44 (7%) were undetected diabetics, 181 (29%) were known diabetics, and 401 (64%) were nondiabetics. In undetected diabetics the PMI rate was higher than in nondiabetics (13.6% vs 3.7%, p = 0.01) and known diabetics (13.6% vs 6.1%, p = 0.11). Multivariate analysis adjusting for covariates confirmed a significantly higher PMI risk in undetected diabetics compared to nondiabetics (odds ratio 6.13, 95% confidence interval 2.07 to 18.13, p = 0.001) and known diabetics (odds ratio 3.73, 95% confidence interval 1.17 to 11.89, p = 0.03). After 1 year, target vessel MI rate was significantly higher in undetected diabetics (p = 0.02) than in nondiabetics, which was related mainly to differences in PMI. Target vessel failure was numerically larger in unknown diabetics than in nondiabetics, but this difference did not reach statistical significance (13.6% vs 8.0%, p = 0.25). In conclusion, undetected diabetics were shown to have an increased risk of PMI.

Comparison of eligible non-enrolled patients and the randomised TWENTE trial population treated with Resolute and Xience V drug-eluting stents.

AIMS: The TWENTE trial recently enrolled more than 80% of all eligible patients, who were randomised to zotarolimus-eluting Resolute or everolimus-eluting XIENCE V stents. In the present study, we investigated whether eligible, non-enrolled patients differed from the randomised TWENTE trial population in baseline characteristics and one-year outcome. METHODS AND RESULTS: Characteristics of 1,709 eligible patients were analysed. Independent external adjudication of clinical events was likewise performed for non-enrolled (n=318) and randomised patients (n=1,391). Non-enrolled and randomised patients did not differ in gender distribution, diabetes mellitus, and clinical presentation, but differed significantly in age and cardiovascular history. Nevertheless, clinical outcome after one year did not differ in the primary composite endpoint target-vessel failure (TVF; 9.8% vs. 8.1%; p=0.34), and its components cardiac death (1.6% vs. 1.2%; p=0.61), target vessel-related myocardial infarction (4.7% vs. 4.6%; p=0.92), and target-vessel revascularisation (3.8% vs. 3.0%; p=0.48). Previous bypass surgery predicted TVF in non-enrolled patients (p=0.001); removal of these patients resulted in identical TVF rates for non-enrolled and randomised patients (7.3% vs. 7.3%; p=0.99). CONCLUSIONS: Despite some differences in baseline characteristics, non-enrolled and randomised patients did not differ in one-year outcome, which was favourable for both populations and may be related to the drug-eluting stents used.

DUrable polymer-based sTent CHallenge of Promus ElemEnt versus ReSolute integrity (DUTCH PEERS): rationale and study design of a randomized multicenter trial in a Dutch all-comers population.

BACKGROUND: Drug-eluting stents (DES) are increasingly used for the treatment of coronary artery disease. An optimized DES performance is desirable to successfully treat various challenging coronary lesions in a broad population of patients. In response to this demand, third-generation DES with an improved deliverability were developed. Promus Element (Boston Scientific, Natick, MA) and Resolute Integrity (Medtronic Vascular, Santa Rosa, CA) are 2 novel third-generation DES for which limited clinical data are available. Accordingly, we designed the current multicenter study to investigate in an all-comers population whether the clinical outcome is similar after stenting with Promus Element versus Resolute Integrity. METHODS: DUTCH PEERS is a multicenter, prospective, single-blinded, randomized trial in a Dutch all-comers population. Patients with all clinical syndromes who require percutaneous coronary interventions with DES implantation are eligible. In these patients, the type of DES implanted will be randomized in a 1:1 ratio between Resolute Integrity versus Promus Element. The trial is powered based on a noninferiority hypothesis. For each stent arm, 894 patients will be enrolled, resulting in a total study population of 1,788 patients. The primary end point is the incidence of target vessel failure at 1-year follow-up. SUMMARY: DUTCH PEERS is the first randomized multicenter trial with a head-to-head comparison of Promus Element and Resolute Integrity to investigate the safety and efficacy of these third-generation DES.

Incidence of periprocedural myocardial infarction following stent implantation: comparison between first- and second-generation drug-eluting stents.

BACKGROUND: First- and second-generation drug-eluting stents (DES) differ in coating materials, which may influence the incidence of periprocedural myocardial infarction (PMI). OBJECTIVE: To compare the incidence of PMI between first- and second-generation DES, using the current Academic Research Consortium (ARC) definition of PMI. METHODS: We assessed 800 patients treated with first- (Taxus Liberté or Endeavor) or second-generation DES (Xience V or Resolute). Each DES group consisted of 200 consecutive patients, who were treated during the transition from first- to second-generation DES. Routine peri-interventional assessment of cardiac biomarkers was performed to compare the incidence of PMI between DES groups according to the updated definition by the ARC: 2x upper reference limit of creatine kinase (CK), confirmed by CK-MB elevation. RESULTS: In 800 patients, a total of 1,522 DES (363 Taxus; 385 Endeavor; 382 Xience V; 392 Resolute) were implanted to treat 1,232 lesions. Patient characteristics did not differ between groups. In patients receiving second-generation DES, more multivessel percutaneous coronary interventions were performed (P = 0.01). The overall incidence of PMI was 4.75%. Between first- and second-generation DES, there was no significant difference in PMI (5.5% vs. 4.0%; P = 0.29). In a multivariate analysis, only the total number of stents implanted (P < 0.001) and presentation with acute coronary syndrome (P = 0.02) were independent predictors of PMI. CONCLUSION: Using the revised ARC definition, we found no significant difference in PMI between first- and second-generation DES. Overall, PMI occurred in 4.75%, which is 58% lower than with use of the historical PMI definition.

[Takotsubo cardiomyopathy; reversible cardiomyopathy induced by stress]. / Viskruikinfarct. Reversibele cardiomyopathie door stressvolle gebeurtenis.

Takotsubo cardiomyopathy was diagnosed in a 79-year-old woman. She visited her husband who had been admitted for primary percutaneous coronary intervention, and during her visit she developed acute chest pain. Further investigation revealed transient left ventricular apical ballooning, diagnosed as takotsubo cardiomyopathy. This clinical syndrome is characterized by transient regional left ventricle wall motion abnormalities without significant epicardial coronary stenosis. It is provoked by stressful events. Especially in elderly women presenting with the clinical features of an ST-elevation myocardial infarction, takotsubo cardiomyopathy should be considered as an alternative diagnosis. Regarding the exact aetiology and pathophysiology many questions remain unanswered. With supportive treatment the prognosis is favourable.

Comparative predictive value of infarct location, peak CK, and ejection fraction after primary PCI for ST elevation myocardial infarction.

OBJECTIVE: Although infarct location may predict prognosis after primary percutaneous coronary intervention (PCI) for ST elevation myocardial infarction, previous studies were powered insufficiently to be able to show whether this association is independent of peak creatine kinase (CK) or left ventricular ejection fraction (LVEF). METHODS: A large-scale, prospective, observational, single-center study was performed including all patients who underwent primary PCI between 1991 and 2004 in Zwolle (The Netherlands). The association between infarct location and 1-year outcome, was compared with the prognostic impact of peak CK and LVEF. RESULTS: Of 4990 patients, 2485 (49.8%) had an anterior infarction. Patients with anterior myocardial infarction had a higher peak CK (2960 vs. 2009 U/l, P<0.001) and a lower LVEF (40.0 vs. 50.0%, P<0.001). Mortality within 1 year was higher in patients with anterior infarction as well as in those with a high peak CK or a low LVEF. After multivariate analyses, patients with anterior infarction still had an increased risk of a high peak CK, a poor LVEF, and also a higher 1-year mortality, odds ratio (OR) 1.35 [95% confidence interval (CI) 1.07-1.70]. Low LVEF was a significant stronger predictor of 1-year mortality, OR 4.4 (95% CI: 2.4-7.8), compared with peak CK, OR 2.0 (95% CI: 1.6-2.5) or anterior location, OR 1.6 (95% CI: 1.3-2.0). CONCLUSION: In patients undergoing primary PCI, location of infarction is an important independent predictor of high peak CK, low LVEF, and increased mortality. LVEF is a strong predictor of 1-year mortality.

Prognostic importance of creatine kinase and creatine kinase-MB after primary percutaneous coronary intervention for ST-elevation myocardial infarction.

BACKGROUND: Although the prognostic significance of creatine kinase (CK) and creatine kinase-MB (CK-MB) after myocardial infarction has been established after thrombolysis or no reperfusion therapy, there is limited evidence of the prognostic importance after primary percutaneous coronary intervention (PCI). METHODS: In this prospective, observational study, individual data from all patients who survived at least 2 days after primary PCI between 1991 and 2004 in our hospital were recorded. The association between enzymatic infarct size (examined by peak CK and peak CK-MB levels, each divided into tertiles) and both left ventricular ejection fraction (LVEF) and 1-year mortality was evaluated. RESULTS: In the study group of 4670 patients, mean peak CK was 2327 U/L (SD 2008) and mean peak CK-MB was 244 U/L (SD 208). Both increased CK and CK-MB were associated with a lower LVEF. A total of 252 patients (5.4%) died between 2 days and 1 year after admission. Both peak CK and peak CK-MB were higher in those who died. Particularly, patients in the highest tertile of either peak CK or peak CK-MB had increased mortality, whereas the differences between the lower tertiles were not significant. In 2738 patients, after multivariable analysis including LVEF, the hazard ratio for 1-year mortality in patients in the highest CK tertile was 2.28 (95% CI 1.32-3.91) and for CK-MB, 1.91 (95% CI 1.11-3.26), compared to those in the other tertiles. CONCLUSIONS: According to this large-scale study, peak CK and peak CK-MB are comparable independent predictors of LV function and 1-year mortality in patients after primary PCI.

Prognostic value of troponin after elective percutaneous coronary intervention: A meta-analysis.

BACKGROUND: Although the prognostic importance of troponin in patients with anacute coronary syndrome is clear, the significance of troponin elevation after elective percutaneous coronary intervention (PCI) is a subject of debate. However, most studies up to now had a small sample size and insufficient events during follow-up. METHODS: Electronic and manual searches were performed of studies reporting on prognosis of troponin after elective PCI. A meta-analysis was done of all suitable studies, with death in follow-up as primary endpoint and the combination of death or nonfatal myocardial infarction in follow-up as secondary endpoint. RESULTS: 20 studies involving 15,581 patients were included. These studies were published between 1998 and 2007. Overall, troponin was elevated after elective PCI in 32.9% of patients. The follow-up period varied between 3 and 67 months (mean 16.3). Increased mortality was significantly associated with troponin elevation after PCI (4.4% vs. 3.3%, P = 0.001; OR 1.35). Furthermore, the combined endpoint of mortality or nonfatal myocardial infarction also occurred more often in patients with post-procedural troponin elevation (8.1% vs. 5.2%, P < 0.001; OR 1.59). CONCLUSIONS: According to this meta-analysis, troponin elevation after elective PCI provides important prognostic information.

Prognostic importance of troponin T and creatine kinase after elective angioplasty.

BACKGROUND: The prognostic importance of elevated cardiac enzymes after elective percutaneous coronary intervention has been debated. Therefore, we performed a prospective observational study to evaluate the prognostic value of postprocedural rise of troponin T and creatine kinase. METHODS: Troponin T (cut-off value 0.05 ng/ml) and creatine kinase (cut-off value 180 IU/l with muscle-brain fraction >4%) were measured 12 h after elective percutaneous coronary intervention in 713 consecutive patients without elevated troponin before the procedure. Primary endpoint was the combined incidence of death, myocardial infarction, stroke, repeat angiography or re-admission because of anginal symptoms during the follow-up period. RESULTS: Troponin was elevated after the procedure in 150 patients (21%) and creatine kinase in 66 pts (9%), with a strong association between increased troponin and creatine kinase. After a mean follow-up of 10.9 months, mortality was low (1%) and not associated with increased troponin or creatine kinase. There was, however, a strong relation between postprocedural troponin and re-admission for angina (p=0.001) or myocardial infarction (p=0.001). Furthermore, troponin rise was significantly associated with an increased risk of the primary endpoint (relative risk 1.55 95% confidence interval 1.01-2.38). After multivariate analysis, troponin elevation but not increased creatine kinase was associated with an increased risk of the primary endpoint (relative risk 1.59 95% confidence interval 1.02-2.47 for troponin elevation versus 1.16 95% confidence interval 0.62-2.15 for increased creatine kinase). CONCLUSION: Increase of troponin T after elective percutaneous coronary intervention has stronger prognostic implication when compared to increased creatine kinase.

Predictors of elevated cardiac troponin T on admission in ST-segment elevation myocardial infarction.

BACKGROUND: In patients with ST-segment elevation acute myocardial infarction (STEMI), elevated cardiac troponin T (cTnT) on admission is associated with poorer outcomes despite early reperfusion. Presentation delay is thought to be the most important factor for the elevation of cTnT on admission. We evaluated presentation delay and other potential predictors of elevated cTnT on admission in patients treated with primary percutaneous coronary interventions (PCI) for STEMI. METHODS: CTnT was measured upon arrival in the PCI centre in 444 patients with acute STEMI. An elevated cTnT was defined as > 0.05 microg/L. RESULTS: The mean age was 61.7 years and patients were admitted at a median of 155 min after symptom onset. Almost 50% had an elevated cTnT on admission. Patients with a positive cTnT on admission were less likely to have successful primary PCI (87 versus 93%, P=0.048) and had significantly higher rates of one-year mortality (4.9 versus 1.3%, P=0.031). There was a significant association between presentation delay and the prevalence of elevated admission cTnT, but even patients with early presentation (<120 min after symptom onset) still had a high prevalence of elevated cTnT (33%). After multivariate analysis, apart from presentation delay, anterior MI location and higher age were independent predictors of elevated cTnT on admission. CONCLUSION: In patients with STEMI, the prevalence of elevated cTnT on admission is high, even in patients with early presentation. Independent predictors of elevated cTnT on admission are presentation delay, increasing age and anterior MI location.

Pre-treatment with clopidogrel and postprocedure troponin elevation after elective percutaneous coronary intervention.

Elevated troponin after elective percutaneous coronary intervention (PCI) has been associated with a worse prognosis. Pretreatment with clopidogrel may be beneficial in patients undergoing PCI. Therefore, a prospective observational study was conducted to address the potential role of clopidogrel in reducing troponin release after elective PCI. TroponinT was measured 12 hours after elective PCI in 656 patients without elevated troponin before PCI. To assess the independent association between pre-treatment with clopidogrel and increased troponin, multivariate analyses were performed. Mean age of the 656 patients was 63.5 years (SD 10.2), 194 patients (30%) were female and 114 patients (17.4%) had diabetes. In 217 patients (33%) troponin was increased after PCI. Of the 330 patients who were not pre-treated with clopidogrel, 118 patients (34%) had increased troponin after the PCI compared to 99 patients (30%) of the 326 patients who were treated with clopidogrel longer than 24 hours before the procedure (p = 0.14). Stratified analyses showed that patients with older age (p = 0.03), previous PCI (p = 0.013), angina CCS 4 (p = 0.03) and multivessel disease (p = 0.04) had a significantly lower risk of troponin increase after pre-treatment with clopidogrel compared to patients without pre-treatment. After adjusting for differences in the other variables, patients who were pre-treated with clopidogrel had a significant lower risk of post-PCI increase of troponin T (odds ratio 0.69, 95% confidence interval 0.49-0.99). Pre-treatment with clopidogrel is associated with a significantly lower incidence of increased troponin after elective PCI. Combined with results of other studies, pre-treatment should be advised in patients waiting for elective PCI.