In-stent restenosis in the drug-eluting stent era

The introduction of the drug-eluting stent (DES) proved to be an important step forward in reducing rates of restenosis and target lesion revascularization after percutaneous coronary intervention. However, the rapid implementation of DES in standard practice and expansion of the indications for percutaneous coronary intervention to high-risk patients and complex lesions also introduced a new problem: DES in-stent restenosis (ISR), which occurs in 3% to 20% of patients, depending on patient and lesion characteristics and DES type. The clinical presentation of DES ISR is usually recurrent angina, but some patients present with acute coronary syndrome. Mechanisms of DES ISR can be biological, mechanical, and technical, and its pattern is predominantly focal. Intravascular imaging can assist in defining the mechanism and selecting treatment modalities. Based upon the current available evidence, an algorithm for the treatment approaches to DES restenosis is proposed.

Quantification and impact of untreated coronary artery disease after percutaneous coronary intervention: the residual SYNTAX (Synergy Between PCI with Taxus and Cardiac Surgery) score

OBJECTIVES

The purpose of this study was to quantify the extent and complexity of residual coronary stenoses following percutaneous coronary intervention (PCI) and to evaluate its impact on adverse ischemic outcomes.

BACKGROUND

Incomplete revascularization (IR) after PCI is common, and most studies have suggested that IR is associated with a worse prognosis compared with complete revascularization (CR). However, formal quantification of the extent and complexity of residual atherosclerosis after PCI has not been performed.

METHODS

The baseline Synergy Between PCI With Taxus and Cardiac Surgery (SYNTAX) score (bSS) from 2,686 angiograms from patients with moderate- and high-risk acute coronary syndrome (ACS) undergoing PCI enrolled in the prospective ACUITY (Acute Catheterization and Urgent Intervention Triage Strategy) trial was determined. The SS after PCI was also assessed, generating the "residual" SS (rSS). Patients with rSS >0 were defined as having IR and were stratified by rSS tertiles, and their outcomes were compared to the CR group.

RESULTS

The bSS was 12.8 ± 6.7, and after PCI the rSS was 5.6 ± 2.2. Following PCI, 1,084 patients (40.4%) had rSS = 0 (CR), 523 (19.5%) had rSS >0 but ≤2, 578 (21.5%) had rSS >2 but ≤8, and 501 patients (18.7%) had rSS >8. Age, insulin-treated diabetes, hypertension, smoking, elevated biomarkers or ST-segment deviation, and lower ejection fraction were more frequent in patients with IR compared with CR. The 30-day and 1-year rates of ischemic events were significantly higher in the IR group compared with the CR group, especially those with high rSS. By multivariable analysis, rSS was a strong independent predictor of all ischemic outcomes at 1 year, including all-cause mortality (hazard ratio: 1.05, 95% confidence interval: 1.02 to 1.09, p = 0.006).

CONCLUSIONS

The rSS is useful to quantify and risk-stratify the degree and complexity of residual stenosis after PCI. Specifically, rSS >8.0 after PCI in patients with moderate- and high-risk ACS is associated with a poor 30-day and 1-year prognosis. (Comparison of Angiomax Versus Heparin in Acute Coronary Syndromes; NCT00093158).

Frequency and Predictors of Stent Thrombosis After Percutaneous Coronary Intervention in Acute Myocardial Infarction

Background—

Concerns persist regarding the risk of stent thrombosis in the setting of primary percutaneous coronary intervention for ST-segment elevation myocardial infarction.

Methods and Results—

The Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial included 3602 patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention who were randomized to heparin plus a glycoprotein IIb/IIIa inhibitor (GPI) (n=1802) versus bivalirudin monotherapy (n=1800). Stents were implanted in 3202 patients, including 2261 who received drug-eluting stents and 861 who received only bare metal stents. Definite or probable stent thrombosis within 2 years occurred in 137 patients (4.4%), including 28 acute events (0.9%), 49 subacute events (1.6%), 32 late events (1.0%), and 33 very late events (1.1%). The 2-year cumulative rates of stent thrombosis were 4.4% with both drug-eluting stents and bare metal stents ( P =0.98) and 4.3% versus 4.6% in patients randomized to bivalirudin monotherapy versus heparin plus a GPI, respectively ( P =0.73). Acute stent thrombosis occurred more frequently in patients assigned to bivalirudin compared with heparin plus a GPI (1.4% versus 0.3%; P <0.001), whereas stent thrombosis after 24 hours occurred less frequently in patients with bivalirudin compared with heparin plus a GPI (2.8% versus 4.4%; P =0.02). Prerandomization heparin and a 600-mg clopidogrel loading dose were independent predictors of reduced acute and subacute stent thrombosis, respectively.

Conclusions—

Stent thrombosis is not uncommon within the first 2 years after primary percutaneous coronary intervention in ST-segment elevation myocardial infarction, and occurs with similar frequency in patients receiving drug-eluting stents versus bare metal stents and bivalirudin alone versus heparin plus a GPI. Optimizing adjunct pharmacology including early antithrombin therapy preloading with a potent antiplatelet therapy may further reduce stent thrombosis in ST-segment elevation myocardial infarction.

Clinical Trial Registration:—

http://www.clinicaltrials.gov . Unique identifier: NCT00433966.

Characterization and clinical significance of right ventricular mechanics in pulmonary hypertension evaluated with cardiovascular magnetic resonance feature tracking

BACKGROUND

Prognosis in pulmonary hypertension (PH) is related to right ventricular (RV) function. Quantification of RV mechanics may offer additive value. The objective of our study is to determine the feasibility and clinical and prognostic value of RV strain analysis by cardiovascular magnetic resonance (CMR) based feature tracking (FT) in PH.

METHODS

We retrospectively enrolled 116 patients (age 52.2 ± 12 years, 73.6 % women) referred to CMR for PH evaluation who underwent right heart catheterization within 1 month. Using dedicated FT software, peak global longitudinal and circumferential RV strain and strain rates (GLS, GCS, GLSR, and GCSR, respectively) were quantified from standard cine images. Using multivariate regression analysis, we evaluated the associations of strain with a composite endpoint of death, lung transplantation, or functional class deterioration.

RESULTS

RV strain analysis was feasible in 110 (95 %) patients. Patients were classified into: Group A (no PH, normal right ventricular ejection fraction [RVEF]; n = 17), Group B (PH, normal RVEF; n = 26), or Group C (PH, abnormal RVEF; n = 67). All strain and strain rate values were reduced in Group C. Furthermore, GCSR was significantly reduced in Group B (-0.92 [-1.0/-0.7]; p < 0.001) compared to Group A (-1.12 [-1.3/-0.9]; p < 0.001). After adjustment for six clinically meaningful covariates, GLS (hazard ratio 1.06; p = 0.026), GLSR (hazard ratio 2.52; p = 0.04), and GCSR (hazard ratio 4.5; p = 0.01) were independently associated with the composite endpoint. GCSR successfully discriminated patients with and without events (p = 0.01).

CONCLUSIONS

Quantification of RV strain with CMR-FT is feasible in the majority of patients, correlates with disease severity, and is independently associated with poor outcomes in PH.

International Prospective Registry of Acute Coronary Syndromes in Patients With COVID-19

BACKGROUND

Published data suggest worse outcomes in acute coronary syndrome (ACS) patients and concurrent coronavirus disease 2019 (COVID-19) infection. Mechanisms remain unclear.

OBJECTIVES

The purpose of this study was to report the demographics, angiographic findings, and in-hospital outcomes of COVID-19 ACS patients and compare these with pre-COVID-19 cohorts.

METHODS

From March 1, 2020 to July 31, 2020, data from 55 international centers were entered into a prospective, COVID-ACS Registry. Patients were COVID-19 positive (or had a high index of clinical suspicion) and underwent invasive coronary angiography for suspected ACS. Outcomes were in-hospital major cardiovascular events (all-cause mortality, re-myocardial infarction, heart failure, stroke, unplanned revascularization, or stent thrombosis). Results were compared with national pre-COVID-19 databases (MINAP [Myocardial Ischaemia National Audit Project] 2019 and BCIS [British Cardiovascular Intervention Society] 2018 to 2019).

RESULTS

In 144 ST-segment elevation myocardial infarction (STEMI) and 121 non-ST-segment elevation acute coronary syndrome (NSTE-ACS) patients, symptom-to-admission times were significantly prolonged (COVID-STEMI vs. BCIS: median 339.0 min vs. 173.0 min; p < 0.001; COVID NSTE-ACS vs. MINAP: 417.0 min vs. 295.0 min; p = 0.012). Mortality in COVID-ACS patients was significantly higher than BCIS/MINAP control subjects in both subgroups (COVID-STEMI: 22.9% vs. 5.7%; p < 0.001; COVID NSTE-ACS: 6.6% vs. 1.2%; p < 0.001), which remained following multivariate propensity analysis adjusting for comorbidities (STEMI subgroup odds ratio: 3.33 [95% confidence interval: 2.04 to 5.42]). Cardiogenic shock occurred in 20.1% of COVID-STEMI patients versus 8.7% of BCIS patients (p < 0.001).

CONCLUSIONS

In this multicenter international registry, COVID-19-positive ACS patients presented later and had increased in-hospital mortality compared with a pre-COVID-19 ACS population. Excessive rates of and mortality from cardiogenic shock were major contributors to the worse outcomes in COVID-19 positive STEMI patients.

Long-term outcomes after transcatheter aortic valve implantation in failed bioprosthetic valves

Aims

Due to bioprosthetic valve degeneration, aortic valve-in-valve (ViV) procedures are increasingly performed. There are no data on long-term outcomes after aortic ViV. Our aim was to perform a large-scale assessment of long-term survival and reintervention after aortic ViV.

Methods and results

A total of 1006 aortic ViV procedures performed more than 5 years ago [mean age 77.7 ± 9.7 years; 58.8% male; median STS-PROM score 7.3% (4.2–12.0)] were included in the analysis. Patients were treated with Medtronic self-expandable valves (CoreValve/Evolut, Medtronic Inc., Minneapolis, MN, USA) (n = 523, 52.0%), Edwards balloon-expandable valves (EBEV, SAPIEN/SAPIEN XT/SAPIEN 3, Edwards Lifesciences, Irvine, CA, USA) (n = 435, 43.2%), and other devices (n = 48, 4.8%). Survival was lower at 8 years in patients with small-failed bioprostheses [internal diameter (ID) ≤ 20 mm] compared with those with large-failed bioprostheses (ID &gt; 20 mm) (33.2% vs. 40.5%, P = 0.01). Independent correlates for mortality included smaller-failed bioprosthetic valves [hazard ratio (HR) 1.07 (95% confidence interval (CI) 1.02–1.13)], age [HR 1.21 (95% CI 1.01–1.45)], and non-transfemoral access [HR 1.43 (95% CI 1.11–1.84)]. There were 40 reinterventions after ViV. Independent correlates for all-cause reintervention included pre-existing severe prosthesis–patient mismatch [subhazard ratio (SHR) 4.34 (95% CI 1.31–14.39)], device malposition [SHR 3.75 (95% CI 1.36–10.35)], EBEV [SHR 3.34 (95% CI 1.26–8.85)], and age [SHR 0.59 (95% CI 0.44–0.78)].

Conclusions

The size of the original failed valve may influence long-term mortality, and the type of the transcatheter valve may influence the need for reintervention after aortic ViV.

Long-term prognosis of patients presenting with ST-segment elevation myocardial infarction with no significant coronary artery disease (from the HORIZONS-AMI trial)

The clinical features and prognosis of patients with ST-segment elevation myocardial infarction (STEMI) and no significant coronary artery disease (CAD) have not been well studied. We examined the outcomes of patients with STEMI in the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial according to the presence or absence of significant CAD. "No-CAD" was defined by the absence of any lesion with a diameter stenosis of ≥30% on quantitative coronary angiography of the baseline coronary angiogram. Of 3,602 patients, 127 (3.5%) had no-CAD. Of these, 86 (67.7%) had angiographically normal coronary arteries, and 41 (32.3%) had mild disease (diameter stenosis <30%). Eight patients had previously been treated with coronary artery bypass grafting. Compared to patients with CAD, patients with no-CAD were younger, had a lower body mass index, were more frequently black, had a lower prevalence of smoking and previous angina, and had a greater left ventricular ejection fraction. Cardiac enzymes were elevated in fewer patients with no-CAD than in those with CAD (63.2% vs 98.7%, p <0.001). At 3 years of follow-up, the patients with no-CAD versus CAD had lower rates of major adverse cardiovascular events (7.7% vs 22.2%, p = 0.002), net adverse clinical events (major adverse cardiovascular events or major bleeding not related to coronary artery bypass grafting, 12.5% vs 26.9%, p = 0.005), and postprocedure coronary revascularization (0% vs 19.5%, p <0.001). The differences in the rates of death or reinfarction, stroke, and major bleeding were not statistically significant. In conclusion, 3.5% of patients with STEMI had no significant CAD. The 3-year prognosis for these patients was favorable compared to that of patients with STEMI and with obstructive CAD.

Stent Thrombosis and Dual Antiplatelet Therapy Interruption With Everolimus-Eluting Stents: Insights From the Xience V Coronary Stent System Trials

BACKGROUND

Whether premature dual antiplatelet therapy (DAPT) interruption is safe in patients receiving cobalt chromium everolimus-eluting stents remains controversial. We sought to examine the relationship between DAPT discontinuation and stent thrombosis (ST) after cobalt chromium everolimus-eluting stents.

METHODS AND RESULTS

Outcomes from 11,219 patients were pooled from 3 randomized trials and 4 registries with 2-year follow-up period after cobalt chromium everolimus-eluting stent implantation. Rates of definite/probable ST were analyzed according to DAPT discontinuation in the following time intervals: 0 to 30, 30 to 90, 90 to 180, 180 to 365, and 365 to 730 days. Eighty-five cases of ST (0.75%) occurred in 83 patients during 2 years, with 41 (48.2%) events occurring within 30 days. The 2-year ST rate in patients interrupting DAPT at any time was similar to that in patients never interrupting DAPT through 2 years (25/4067 [0.63%] versus 58/7152 [0.83%] respectively; P=0.27]. By propensity and DAPT usage-adjusted multivariable analysis, permanent DAPT discontinuation before 30 days was independently associated with the occurrence of ST (hazard ratio [95% confidence interval], 26.8 [8.4-85.4]; P<0.0001), whereas permanent DAPT discontinuation in any interval after 90 days was not associated with ST. Only 2 ST events occurred after DAPT discontinuation between 30 and 90 days (both between 30 and 60 days), and the association between permanent DAPT discontinuation and ST during this period is unclear (hazard ratio [95% confidence interval], 8.7 [2.0-37.3]; P=0.004 for adjusted analysis and 3.4 [0.8-13.8]; P=0.07 for the unadjusted analysis).

CONCLUSIONS

In this large pooled experience, permanent DAPT discontinuation before 30 days after cobalt chromium everolimus-eluting stent implantation was strongly associated with ST, whereas DAPT discontinuation beyond 90 days appeared safe.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00180310, NCT00180479, NCT00307047, NCT00402272, NCT00496938, NCT00676520, and NCT00631228.

Impact of leukocyte count on mortality and bleeding in patients with myocardial infarction undergoing primary percutaneous coronary interventions: analysis from the Harmonizing Outcome with Revascularization and Stent in Acute Myocardial Infarction trial

BACKGROUND

The relationship between white blood cell count (WBCc) and mortality in patients with ST-segment-elevation acute myocardial infarction treated with percutaneous coronary intervention is poorly understood. Furthermore, whether there is a relationship between WBCc and risk of noncardiac mortality and bleeding after percutaneous coronary intervention is unknown.

METHODS AND RESULTS

The baseline WBCc was available in 3193 of 3345 patients (95.5%) who underwent percutaneous coronary intervention in the Harmonizing Outcome With Revascularization and Stent in Acute Myocardial Infarction (HORIZONS-AMI) trial. In a propensity-adjusted multivariable analysis, WBCc was an independent predictor of 1-year cardiac mortality (hazard ratio, 1.15; 95% confidence interval, 1.09 to 1.22), noncardiac mortality (hazard ratio, 1.19; 95% confidence interval, 1.10 to 1.29), and major bleeding (hazard ratio, 1.08; 95% confidence interval, 1.04 to 1.12). After adjustment for baseline creatinine phosphokinase levels and left ventricular ejection fraction, WBCc remained an independent predictor of 1-year all-cause mortality and cardiac mortality. In patients matched for baseline creatinine phosphokinase levels at hospital admission, the median peak creatinine phosphokinase level was significantly higher in patients with high WBCc (>11 000 per 1 mm(3)) compared with low WBCc (1851 U/L [range, 880-3307 U/L] versus 1241 U/L [range, 540 to 2,78], respectively; P<0.0001). In this subgroup of patients, WBCc was an independent correlate of peak creatinine phosphokinase level, and remained an independent predictor of 1-year mortality.

CONCLUSIONS

In patients with ST-segment-elevation acute myocardial infarction undergoing percutaneous coronary intervention, elevated baseline WBCc is an independent predictor of infarct size, as assessed by peak creatinine phosphokinase level, and of 1-year cardiac mortality, noncardiac mortality, and major bleeding.

Clinical follow-up 3 years after everolimus- and paclitaxel-eluting stents: a pooled analysis from the SPIRIT II (A Clinical Evaluation of the XIENCE V Everolimus Eluting Coronary Stent System in the Treatment of Patients With De Novo Native Coronary Artery Lesions) and SPIRIT III (A Clinical Evaluation of the Investigational Device XIENCE V Everolimus Eluting Coronary Stent System [EECSS] in the Treatment of Subjects With De Novo Native Coronary Artery Lesions) randomized trials

OBJECTIVES

The purpose of this study was to investigate long-term 3-year clinical outcomes of an everolimus-eluting stent (EES) versus a paclitaxel-eluting stent (PES).

BACKGROUND

Compared with PES, EES reduced target vessel failure and major adverse cardiac events at 2 years. Whether the benefits of EES are sustained at 3 years has not been reported.

METHODS

In the SPIRIT II (A Clinical Evaluation of the XIENCE V Everolimus Eluting Coronary Stent System in the Treatment of Patients With De Novo Native Coronary Artery Lesions) and SPIRIT III (A Clinical Evaluation of the Investigational Device XIENCE V Everolimus Eluting Coronary Stent System [EECSS] in the Treatment of Subjects With De Novo Native Coronary Artery Lesions) trials, 1,302 patients were randomly assigned to EES (n = 892) or PES (n = 410). We report the 3-year clinical follow-up of this patient-level pooled analysis.

RESULTS

At 3 years, EES compared with PES resulted in a significant reduction in myocardial infarction (3.8% vs. 6.7%; relative risk [RR]: 0.56; 95% confidence interval [CI]: 0.34 to 0.94; p = 0.04), and target lesion revascularization (6.8% vs. 12.7%; RR: 0.53; 95% CI: 0.37 to 0.77; p = 0.001). Everolimus-eluting stents resulted in a significant reduction in target vessel failure (13.7% vs. 19.5%; RR: 0.70; 95% CI: 0.54 to 0.92; p = 0.01), and major adverse cardiac events (9.1% vs. 16.3%; RR: 0.56; 95% CI: 0.41 to 0.76; p = 0.0004). The cumulative rates of Academic Research Consortium-defined definite or probable stent thrombosis were 1.2% in EES patients and 1.9% in PES patients (RR: 0.64; 95% CI: 0.25 to 1.68; p = 0.43).

CONCLUSIONS

In this patient-level pooled analysis, EES compared with PES resulted in a significant and persistent reduction in target vessel failure and major adverse cardiac events at 3 years due to fewer myocardial infarction and ischemic target lesion revascularization events, which is consistent with superior safety and efficacy of the EES platform.

Pregnancy-associated spontaneous coronary artery dissection: insights from a case series of 13 patients

AIMS

We sought to present a series of 13 pregnancy-associated spontaneous coronary artery dissection (P-SCAD), their angiographic and multimodal imaging findings, acute phase treatment, and outcomes.

METHODS AND RESULTS

Between 2005 and 2015, 13 cases of P-SCAD were collected from a database of 11 tertiary hospitals. The mean age was 33.8 ± 3.7 years; most patients had no risk factors for coronary artery disease, and the majority were multiparous. P-SCAD occurred during the puerperium in 12 patients with a median time of 10 days. Only one patient presented with P-SCAD in the 37th week of pregnancy, and she was the only patient who died in this series. Six patients (46%) presented with ST-segment elevation acute myocardial infarction (STEMI), six (46%) presented with non-STEMI, and one presented with unstable angina; one-third of women had cardiogenic shock. In 12 patients, the dissection involved the left anterior descending or circumflex artery, and it extended to the left main coronary artery in 6 patients. Intravascular ultrasound or optical coherence tomography helped to confirm diagnosis and guide treatment in 46% of cases. Seven women were managed clinically; percutaneous coronary intervention was performed in five cases, and coronary artery bypass grafting was performed in one patient.

CONCLUSION

In these 13 cases of P-SCAD, clinical presentation commonly included acute myocardial infarction and cardiogenic shock. Multivessel dissections and involvement of the left coronary artery and left main coronary artery were highly prevalent. Clinicians must be aware of angiographic appearances of P-SCAD for prompt diagnosis and management in these high-risk patients.

Evidence-based management of patients undergoing PCI: contrast-induced acute kidney injury

Contrast-induced acute kidney injury (CI-AKI) is one of the leading causes of hospital-acquired acute kidney injury. CI-AKI is highly prevalent in patients with well-known risk factors, including older age, chronic renal insufficiency, congestive heart failure, and diabetes. Thus far, no strategies have been shown to be effective in preventing CI-AKI beyond thorough patient selection, minimizing the amount of contrast agent, and meticulous hydration of the patient. The role of various drugs in preventing CI-AKI is still controversial and warrants future studies. Despite the remaining uncertainty regarding the degree of nephrotoxicity produced by various contrast agents, nonionic low-osmolar contrast media may be preferred in patients at high risk for CI-AKI.

Outcomes of patients with coronary artery perforation complicating percutaneous coronary intervention and correlations with the type of adjunctive antithrombotic therapy: pooled analysis from REPLACE-2, ACUITY, and HORIZONS-AMI trials

BACKGROUND

The lack of a specific counteragent to bivalirudin may complicate the management of patients with coronary artery (CA) perforation during percutaneous coronary intervention (PCI).

AIM

Assess outcomes of patients with CA perforation from three PCI trials comparing intravenous bivalirudin with provisional glycoprotein (GP) IIb/IIIa inhibition versus unfractionated heparin (UFH) plus GP IIb/IIIa.

METHODS

A pooled analysis of patients treated with PCI in three randomized trials including REPLACE-2, ACUITY, and HORIZONS-AMI.

RESULTS

Among a total of 12,921 patients, CA perforation occurred in 35 patients (0.27%). By multivariable analysis, baseline creatinine clearance was the only independent predictor of CA perforation (per 10 mL/min decrease, odds ratio [95% confidence interval]= 1.28 [1.11, 1.47], P = 0.0007). At 30 days, patients with versus without CA perforation had significantly (all P values < or =0.001) higher rates of 30-day mortality (11.4% vs. 1.0%), myocardial infarction (MI) [Q wave: 22.9% vs. 5.7%; non-Q wave: 17.1% vs. 4.9%], target vessel revascularization (TVR) [20.1% vs. 1.8%], and composite end-point of death/MI/TVR (31.4% vs. 7.8%). Patients assigned to bivalirudin versus UFH plus a GP IIb/IIIa inhibitor had nonsignificantly lower rates of death (0% vs. 18.8%, P = 0.08), similar rates of MI (26.7% vs. 25.0%, P = 0.92), significantly lower rates of TVR (6.7% vs. 37.5%, P = 0.04), and similar rates of the composite end-point of death/MI/TVR (35.5% vs. 26.7%, P = 0.54).

CONCLUSION

In three PCI trials, treatment of patients experiencing CA perforation with adjunctive antithrombotic therapy of bivalirudin monotherapy was not associated with worse outcomes compared to treatment with UFH plus GP IIb/IIIa inhibitors.

Incidence and clinical consequences of acquired thrombocytopenia after antithrombotic therapies in patients with acute coronary syndromes: results from the Acute Catheterization and Urgent Intervention Triage Strategy (ACUITY) trial

BACKGROUND

The aim of the study was to investigate the incidence and clinical consequences of acquired thrombocytopenia in patients with acute coronary syndromes (ACS) in the ACUITY trial.

METHODS

We examined 10,836 patients with ACS randomized to receive heparin plus glycoprotein (GP) IIb/IIIa inhibitor, bivalirudin plus GP IIb/IIIa inhibitor, or bivalirudin monotherapy.

RESULTS

Acquired thrombocytopenia developed in 740 (6.8%) patients; mild (100,000-150,000 platelets/mm³), moderate (50,000-100,000 platelets/mm³), and severe (< 50,000 platelets/mm³) developed in 656 (6%), 51 (0.5%), and 33 (0.3%) patients, respectively. Patients with acquired thrombocytopenia, compared with those without, were more likely to develop major bleeding (14% vs 4.3%, P < .0001) at 30 days and had higher rates of mortality (6.5% vs 3.4%, P < .0001) at 1 year. By multivariate analysis, acquired thrombocytopenia was an independent predictor of major bleeding at 30 days (hazard ratio [HR] 1.68, 95% CI 1.04-2.72, P = .03). Moderate and severe acquired thrombocytopenia were predictors of mortality at 1 year (HR 2.89, 95% CI 0.92-9.06, P = .06, and HR 3.41, 95% CI 1.09-10.68, P = .03, respectively). Compared to heparin plus GP IIb/IIIa inhibitor, bivalirudin monotherapy was associated with less declines in platelet count by >25% (7.6% vs 5.6%, P = .0009) and >50% (1.4% vs 0.7%, P = .004) from baseline.

CONCLUSIONS

Acquired thrombocytopenia occurs in approximately 1 in 14 patients with ACS treated with antithrombin and antiplatelet medications and is strongly associated with hemorrhagic and ischemic complications. Compared to an anticoagulant regimen including a GP IIb/IIIa inhibitor, administration of bivalirudin monotherapy appears to be associated with less frequent declines in platelet count.