Ernest L. Mazzaferri

Cardiac Magnetic Resonance With Edema Imaging Identifies Myocardium at Risk and Predicts Worse Outcome in Patients With Non-ST-Segment Elevation Acute Coronary Syndrome

OBJECTIVESnThe aim of this study was to define the prevalence and significance of myocardial edema in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS).nnnBACKGROUNDnMost patients with NSTE-ACS undergo angiography, yet not all have obstructive coronary artery disease (CAD) requiring revascularization. Identifying patients with myocardium at risk could enhance the effectiveness of an early invasive strategy. Cardiac magnetic resonance (CMR) can demonstrate edematous myocardium subjected to ischemia but has not been used to evaluate NSTE-ACS patients.nnnMETHODSnOne hundred consecutive patients with NSTE-ACS were prospectively enrolled to undergo 30-min CMR, including T2-weighted edema imaging and late gadolinium enhancement before coronary angiography. Clinical management including revascularization decision-making was performed without CMR results.nnnRESULTSnOf 88 adequate CMR studies, 57 (64.8%) showed myocardial edema. Obstructive CAD requiring revascularization was present in 87.7% of edema-positive patients versus 25.8% of edema-negative patients (p < 0.001). By multiple logistic regression analysis after adjusting for late gadolinium enhancement, perfusion, and wall motion scores, TIMI risk score was not predictive of obstructive CAD. Conversely, an increase in T2 score by 1 U increased the odds of subsequent coronary revascularization by 5.70 times (95% confidence interval: 2.38 to 13.62, p < 0.001). Adjusting for peak troponin-I, patients with edema showed a higher hazard of a cardiovascular event or death within 6 months after NSTE-ACS compared with those without edema (hazard ratio: 4.47, 95% confidence interval: 1.00 to 20.03; p = 0.050).nnnCONCLUSIONSnIn NSTE-ACS patients, rapid CMR identifies reversibly injured myocardium due to obstructive CAD and predicts worse outcomes. Identifying myocardium at risk may help direct appropriate patients toward early invasive management.

Incidence, Predictors, and Impact of Post-Discharge Bleeding After Percutaneous Coronary Intervention.

BACKGROUNDnThe incidence, predictors, and prognostic impact of post-discharge bleeding (PDB) after percutaneous coronary intervention (PCI) with drug-eluting stent (DES) implantation are unclear.nnnOBJECTIVESnThis study sought to characterize the determinants and consequences of PDB after PCI.nnnMETHODSnThe prospective ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) study was used to determine the incidence and predictors of clinically relevant bleeding events occurring within 2 years after hospital discharge. The effect of PDB on subsequent 2-year all-cause mortality was estimated by time-adjusted Cox proportional hazards regression.nnnRESULTSnAmong 8,582 all-comers who underwent successful PCI with DES in the ADAPT-DES study, PDB occurred in 535 of 8,577 hospital survivors (6.2%) at a median time of 300 days (interquartile range: 130 to 509 days) post-discharge. Gastrointestinal bleeding (61.7%) was the most frequent source of PDB. Predictors of PDB included older age, lower baseline hemoglobin, lower platelet reactivity on clopidogrel, and use of chronic oral anticoagulation therapy. PDB was associated with higher crude rates of all-cause mortality (13.0% vs. 3.2%; p < 0.0001). Following multivariable adjustment, PDB was strongly associated with 2-year mortality (hazard ratio [HR]: 5.03; p < 0.0001), with an effect size greater than that of post-discharge myocardial infarction (PDMI) (HR: 1.92; p = 0.009).nnnCONCLUSIONSnAfter successful PCI with DES in an unrestricted patient population, PDB is not uncommon and has a strong relationship with subsequent all-cause mortality, greater that that associated with PDMI. Efforts to reduce PDB may further improve prognosis after successful DES implantation. (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents [ADAPT-DES]; NCT00638794).

Diagnostic Performance of Treadmill Exercise Cardiac Magnetic Resonance: The Prospective, Multicenter Exercise CMR's Accuracy for Cardiovascular Stress Testing (EXACT) Trial

Background Stress cardiac magnetic resonance (CMR) has typically involved pharmacologic agents. Treadmill CMR has shown utility in single‐center studies but has not undergone multicenter evaluation. Methods and Results Patients referred for treadmill stress nuclear imaging (SPECT) were prospectively enrolled across 4 centers. After rest 99mTc SPECT, patients underwent resting cine CMR. In‐room stress was then performed using an MR‐compatible treadmill with continuous 12‐lead electrocardiogram monitoring. At peak stress, 99mTc was injected, and patients rapidly returned to the MR scanner isocenter for real‐time, free‐breathing stress cine and perfusion imaging. After recovery, cine and rest perfusion followed by late gadolinium enhancement acquisitions concluded CMR imaging. Stress SPECT was then acquired in adjacent nuclear laboratories. A subset of patients not referred for invasive coronary angiography within 2 weeks of stress underwent coronary computed tomography angiography. Angiographic data available in 94 patients showed sensitivity of 79%, specificity of 99% for exercise CMR with positive predictive value of 92% and negative predictive value of 96%. Agreement between treadmill stress CMR and angiography was strong (κ=0.82), and moderate between SPECT and angiography (κ=0.46) and CMR versus SPECT (κ=0.48). Conclusions The multicenter EXACT trial indicates excellent diagnostic value of treadmill stress CMR in typical patients referred for exercise SPECT.

Two-year outcomes after percutaneous coronary intervention of calcified lesions with drug-eluting stents

BACKGROUNDnPercutaneous coronary intervention (PCI) of lesions with coronary arterial calcification (CAC) is common and has been historically associated with an increased risk of adverse events. Whether the association between target lesion calcification (CAC) and outcomes differ across drug-eluting stent generation or between patients with high vs. low residual platelet reactivity (PR) remains unknown. We assessed the association of CAC with adverse ischemic and bleeding events among patients undergoing contemporary PCI with drug-eluting stents (DES).nnnMETHODSnWe included all 8582 patients who underwent successful PCI with DES in the prospective ADAPT-DES study. Patients were grouped according to whether or not they had CAC. We used a multivariable logistic regression analysis to determine independent predictors of CAC. We assessed the 2-year risk of major adverse cardiac events (MACE: Death, myocardial infarction, or stent thrombosis) and bleeding by constructing Kaplan-Meier curves and fitting unadjusted and adjusted Cox proportional hazards models. We assessed the influence of DES generation and PR on the effect of CAC on outcomes by including interaction terms in the models.nnnRESULTSnCAC was present in 2644 (30.8%) patients. Age, smoking, hypertension, hyperlipidemia, insulin-treated diabetes, hemodialysis, and peripheral artery disease were independent predictors of CAC. Having a CAC was associated with increased unadjusted and adjusted hazards for 2-year MACE and bleeding. The association between CAC and ischemic outcomes was consistent across DES generations and PR (pinteraction>0.05).nnnCONCLUSIONnContemporary DES PCI of calcified lesions is common and is associated with an increased risk of ischemic and bleeding complications.

Proton Pump Inhibitors, Platelet Reactivity, and Cardiovascular Outcomes After Drug-Eluting Stents in Clopidogrel-Treated Patients The ADAPT-DES Study

Background—Certain proton pump inhibitors (PPIs) interfere with clopidogrel metabolism, potentially attenuating P2Y12 receptor inhibition. Previous observational and randomized trials report conflicting results regarding the clinical significance of this pharmacological interaction. We examined the interaction between concomitant administration of PPI and clopidogrel on platelet reactivity and clinical outcomes in the large-scale, prospective Assessment of Dual AntiPlatelet Therapy With Drug-Eluting Stents study. Methods and Results—On-treatment P2Y12 platelet reactivity testing was performed using the VerifyNow assay after clopidogrel loading and successful drug-eluting stent implantation at 11 sites in the United States and Germany. PPIs were prescribed at the discretion of treating physicians; patients were followed for 2 years. High platelet reactivity was defined as P2Y12 reactivity units >208. Of 8582 enrolled patients, 2697 (31.4%) were taking a PPI at the time of coronary intervention. After adjustment for differences in baseline characteristics, PPI use was independently associated with high platelet reactivity (odds ratio, 1.38: 95% confidence interval, 1.25–1.52, P=0.0001). A total of 2162 (25.2%) patients were prescribed a PPI at hospital discharge. In a propensity-adjusted multivariable analysis, discharge PPI use was independently associated with increased risk for postdischarge major adverse cardiac events (cardiac death, myocardial infarction, or ischemia-driven target lesion revascularization) at 2-year follow-up (hazard ratio, 1.21; 95% confidence interval, 1.04–1.42, P=0.02). Conclusions—In patients treated with clopidogrel after successful drug-eluting stents implantation, the concomitant administration of PPI was associated with high platelet reactivity and a greater rate of adverse outcomes during long-term follow-up. Additional studies are warranted to determine the risk–benefit ratio of PPIs in patients with drug-eluting stents treated with clopidogrel. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00433966.

Impact of Aspirin and Clopidogrel Hyporesponsiveness in Patients Treated With Drug-Eluting Stents: 2-Year Results of a Prospective, Multicenter Registry Study

OBJECTIVESnIn this analysis of 2-year outcomes in the ADAPT-DES (Assessment of Dual AntiPlatelet Therapy with Drug-Eluting Stents) study, the authors sought to examine the independent associations between platelet reactivity to both aspirin and clopidogrel and subsequent outcomes.nnnBACKGROUNDnThe relationship between platelet reactivity and long-term adverse events following implantation of drug-eluting stents (DES) has been incompletely characterized.nnnMETHODSnThe ADAPT-DES study was a multicenter registry of patients undergoing routine platelet function testing following percutaneous coronary intervention with DES. The primary study endpoint was definite or probable stent thrombosis (ST); other endpoints were all-cause mortality, myocardial infarction, and clinically relevant bleeding.nnnRESULTSnA total of 8,582 patients were enrolled between 2008 and 2010; 46.3% of patients were on dual antiplatelet therapy at 2 years without discontinuation. At 2 years, definite or probable ST occurred in 92 patients (1.07%). In patientsxa0treated with dual antiplatelet therapy continuously for 2 years, high platelet reactivity on clopidogrel was independently associated with definite or probable ST (adjusted hazard ratio [HR]: 2.16; 95% confidence interval [CI]: 1.27 to 3.67; pxa0= 0.003), myocardial infarction (adjusted HR: 1.35; 95% CI: 1.05 to 1.74; pxa0= 0.02), freedom from clinically relevant bleeding (adjusted HR: 0.74; 95% CI: 0.62 to 0.90; pxa0= 0.002), and all-cause mortality (adjusted HR: 1.36; 95% CI: 1.01 to 1.85; pxa0= 0.04). Between years 1 and 2, high platelet reactivity was not associated with the very late ST and in patients on aspirin monotherapy, aspirin hyporesponsiveness was not associated with adverse outcomes.nnnCONCLUSIONSnThe present study confirms the strong relationship of high platelet reactivity on clopidogrel to 2-year ischemic and bleeding outcomes after DES. The majority of stent-related events occurred within the first year.

Relationship Between Platelet Reactivity and Culprit Lesion Morphology: An Assessment From the ADAPT-DES Intravascular Ultrasound Substudy

OBJECTIVESnThis study evaluated the relationship between platelet reactivity and plaque morphology using grayscale and radiofrequency intravascular ultrasound (IVUS) virtual histology (VH).nnnBACKGROUNDnRecent studies have reported that high on-treatment platelet reactivity (HPR) is associated with higher plaque volume and the presence of multivessel disease; however, the association between HPR and plaque morphology has not been evaluated.nnnMETHODSnThe ADAPT-DES (Dual AntiPlatelet Therapy With Drug Eluting Stents) intravascular ultrasound substudy was a prospective, multicenter, observational study of 8,582 patients undergoing percutaneous coronary intervention with drug-eluting stents in whom platelet reactivity on clopidogrel was assessed routinely. The current analysis included 909 culprit lesions from 773 patients with pre-intervention grayscale IVUS and IVUS-VH. HPR was defined as platelet reactivity >208 P2Y12 reaction unit in point-of-care P2Y12 testing by the VerifyNow assay, measured during steady-state platelet inhibition in patients receiving an antiplatelet agent.nnnRESULTSnHPR was associated with 3-vessel coronary artery disease (31.0% vs. 24.4%; pxa0= 0.04). The incidence of fibroatheroma was higher in patients with HPR than those without HPR (77.1% vs. 68.9%; pxa0= 0.01). The HPR group had larger percent plaque and media volume (plaque and media/external elastic membrane volume: 58.1% [95% confidence interval (CI): 57.1% to 59.0%] vs. 56.6% [95% CI: 55.8% to 57.5%]; pxa0= 0.03) and plaque burden at the minimum lumenxa0site (76.7% [95% CI: 75.7% to 77.8%] vs. 75.0% [95% CI: 74.0% to 76.0%]; pxa0= 0.02). Despite a similar prevalence ofxa0attenuated plaque, patients with HPR had longer culprit lesion attenuated plaque length (8.0 [95% CI: 7.0 to 9.1] mm vs. 6.5 [95% CI: 5.9 to 7.1] mm; pxa0= 0.01). On multivariate analysis, the presence of angiographic calcium (odds ratioxa0[OR]: 1.85: 95% CI: 1.33 to 2.56; pxa0= 0.0002) and HPR (OR: 1.45; 95% CI: 1.05 to 2.01; pxa0= 0.02) were independent predictors for a culprit lesion fibroatheroma.nnnCONCLUSIONSnHPR was associated with increased culprit lesion atherosclerotic burden and adverse plaque morphology among patients undergoing percutaneous coronary intervention. Platelet reactivity might be associated with not only blood clot formation, but also severity of atherosclerosis. (Assessment of Dual AntiPlatelet Therapy With Drug Eluting Stents [ADAPT-DES]; NCT00638794).

Impact of Anemia on Platelet Reactivity and Ischemic and Bleeding Risk: From the Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents Study.

Anemic patients remain at increased risk of ischemic and bleeding events. Whether the effects of hemoglobin levels on thrombotic and bleeding risk are independent of platelet reactivity on clopidogrel, however, remains unknown. Patients from the Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents study were categorized by the presence of anemia at baseline, defined according the World Health Organization criteria. Platelet reactivity was measured with VerifyNow assay; high platelet reactivity (HPR) on clopidogrel was defined as platelet reactive units value >208. Of 8,413 patients included in the study cohort, 1,816 (21.6%) had anemia. HPR was more prevalent in patients with anemia (58.3% vs 38.4%; p <0.001), an association that persisted after multivariate adjustment (adjusted odds ratio: 2.04; 95% confidence interval [CI]: 1.82 to 2.29; p <0.0001). Patients with anemia had higher 2-year rates of major adverse cardiac events (9.5% vs 5.6%; p <0.0001), major bleeding (11.8% vs 7.7%; p <0.0001), and all-cause mortality (4.0% vs 1.4%; p <0.0001); however, after adjustment for baseline clinical confounders, including HPR, anemia was no longer significantly associated with major adverse cardiac events but was still independently associated with all-cause mortality (adjusted HR 1.61, 95% CI 1.23 to 2.12; p <0.0001) and major bleeding (adjusted HR 1.42, 95% CI 1.20 to 1.68; p <0.0001). The effect of HPR on clinical outcomes was uniform according to anemia status, without evidence of interaction. In conclusion, anemia independently correlated with HPR. After percutaneous coronary intervention with drug-eluting stents, anemia at baseline was significantly associated with higher 2-year hemorrhagic and mortality risk; conversely, its association with ischemic risk was attenuated after multivariate adjustment, including HPR.

The Impact of Timing of Ischemic and Hemorrhagic Events on Mortality After Percutaneous Coronary Intervention: The ADAPT-DES Study.

OBJECTIVESnThe aim of this study was to understand the impact of the timing of ischemic and hemorrhagic events after percutaneous coronary intervention (PCI) with drug-eluting stents on subsequent mortality.nnnBACKGROUNDnThese events have been strongly associated with subsequent death.nnnMETHODSnIn the multicenter, prospective ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug Eluting Stents) study, patients at 11 clinical sites with successful PCI with drug-eluting stents underwent assessment of platelet function and were followed for 2 years. Events occurring after PCI-definite or probable stent thrombosis (ST), myocardial infarction (MI) not related to ST, and clinically relevant bleeding (CB)-were classified as early (≤30 days), late (31 to 365xa0days), or very late (>365 days). Mortality within 30 days of each event was estimated by Kaplan-Meier methodology. Cox regression multivariate modeling was used to analyze the relationship between each event (as a time-updated variable) and mortality over the entire study period.nnnRESULTSnAmong 8,582 patients, 1,060 (12.4%) had events-691 (8.1%) had CB, 294 (3.4%) had MI, and 75 (0.9%) had ST-and 7,522 (87.6%) had no events. The highest risk was associated with early ST (38.5% mortality at 30 days after the event), whereas very late MI (7.5%) and late CB (7.3%) were less dangerous. By multivariate analysis, each event was independently predictive of death, with hazard ratios of 2.4, 1.8, and 11.4, respectively (pxa0< 0.0001).nnnCONCLUSIONSnApproximately 1 in 8 patients successfully undergoing PCI with drug-eluting stents had CB, MI, or ST during the ensuing 2 years. These events are associated with an increased hazard of mortality, particularly within the first 30 days following the event, warranting efforts to prevent their occurrence.

Relation Between Platelet Count and Platelet Reactivity to Thrombotic and Bleeding Risk: From the Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents Study.

Whether the association between platelet count (PC) and thrombotic and bleeding risk is independent of or varies by residual platelet reactivity to antiplatelet therapies is unclear. We sought to investigate the independent and combined effects of PC and platelet reactivity on thrombotic and bleeding risk after coronary artery implantation of drug-eluting stents (DES). Patients enrolled in the prospective, multicenter Assessment of Dual AntiPlatelet Therapy with Drug-Eluting Stents study were stratified by PC tertiles. The study cohort comprised 8,402 patients. By linear regression analysis, lower PC was strongly and independently associated with higher platelet reactive units (PRUs) on clopidogrel. After multivariable adjustment (including PRU and aspirin reactive units), high, but not low, PC tertile was independently associated with higher risk of thrombotic complications, including spontaneous myocardial infarction and stent thrombosis. Although no independent association was observed between PC tertiles and hemorrhagic risk, both high and low PC tertiles were associated with increased risk for all-cause mortality. After stratification of PC tertiles by tertiles of PRUs, the crude risk of thrombotic complications was highest in patients in the high PC and high PRU tertiles. By multivariable adjustment, PRU increases were uniformly associated with higher risk of thrombotic events across PC tertiles, without evidence of interaction. In conclusion, higher PCs and higher PRUs act independently and synergistically in determining thrombotic risk. Alongside PRU, PCs could be a simple hematological parameter to consider for risk stratification and in tailoring duration and potency of pharmacologic platelet inhibition after DES implantation.