Pathophysiology of cardiogenic shock complicating acute myocardial infarction.

Cardiogenic shock is a rapidly progressive, often fatal complication of acute myocardial infarction. A vicious circle of ischemia, decreased cardiac output and reinfarction progress to left ventricular failure and death. The fundamental pathophysiology of this cascade and other mechanisms beyond the classic paradigm of ischemia and dysfunction are discussed in detail.

An early revascularization strategy is associated with a survival benefit for diabetic patients in cardiogenic shock after acute myocardial infarction.

BACKGROUND: The role of diabetes mellitus (DM) in cardiogenic shock (CS) complicating an acute myocardial infarction (AMI) is not well understood. Previous studies have reported an in-hospital mortality rate for patients with DM and CS of about 60%. OBJECTIVES: This study compares the 1-year mortality rates of patients with DM and those without (NDM) and evaluates early revascularization (ERV) compared with initial medical stabilization (IMS) in patients with DM and CS. METHODS: Baseline characteristics, clinical and hemodynamic measures, and management were compared for 90 patients (31%) with DM and 198 with NDM (69%) who were randomized to ERV or IMS in the SHOCK Trial. RESULTS: When compared with NDM, patients with DM were of similar age but had higher rates of prior MI (44.4 vs. 27.8%, p = 0.007) and hypertension (56.2 vs. 42.5%, p = 0.04). The DM group had a lower rate of fibrinolytic therapy (44.4 vs. 60.1%, p = 0.02). In patients randomized to ERV, patients with DM had a higher rate of coronary artery bypass grafting (CABG) (50.0 vs. 30.9%, p = 0.03) despite similar rates of triple-vessel disease. The 1-year mortality rates in both groups were equivalent (58.9%). One-year mortality was not associated with diabetes (hazard ratio [HR] 1.02, 95% CI, 0.73-1.42, p = 0.91). The benefit of an ERV strategy was similar (HR [DM] 0.62; HR [NDM] 0.75, p = 0.58). Even after adjusting for the imbalance in CABG rates, 1-year mortality was not associated with DM. CONCLUSION: Diabetes mellitus is not a predictor of 1-year mortality in CS after AMI. The benefit from an ERV strategy is similar for DM and NDM. The management strategies and influence of DM on mortality in CS deserve further evaluation.

Gender differences in outcomes after primary angioplasty versus primary stenting with and without abciximab for acute myocardial infarction: results of the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) trial.

BACKGROUND: Women with acute myocardial infarction (AMI) undergoing primary angioplasty have higher rates of morbidity and mortality than do men. Whether contemporary interventional treatment strategies have improved outcomes for women compared with men is unknown. METHODS AND RESULTS: In the CADILLAC trial, 2082 patients (27% women) with AMI within 12 hours of symptom onset were randomized to balloon angioplasty (PTCA; n=518), PTCA+abciximab (n=528), stenting (n=512), and stenting+abciximab (n=524). As compared with men, women had a lower body surface area; had a greater prevalence of diabetes, hypertension, and hyperlipidemia; experienced significant delays to treatment; and had better baseline and final TIMI grade 3 flows. Unadjusted 1-year event rates were higher for women, including death (7.6% versus 3.0%, P<0.001), ischemic target-vessel revascularization (TVR; 16.7% versus 12.1%, P=0.006), and major adverse cardiac events (MACE; 23.9% versus 15.3%, P<0.001). Female gender was an independent predictor of MACE and bleeding complications, although comorbid risk factors and body surface area but not gender predicted 1-year death. For women, primary stenting resulted in a reduction in 1-year MACE from 28.1% to 19.1% (P=0.01) and in ischemic TVR from 20.4% to 10.8% (P=0.002) compared with PTCA. The addition of abciximab to primary stenting significantly reduced the 30-day ischemic TVR without increasing bleeding or stroke rates. CONCLUSIONS: The higher mortality rate in women compared with men after interventional treatment for AMI may be explained by differences in body size and clinical risk factors, although female gender remains an important independent determinant of overall adverse outcomes. For women in the CADILLAC trial, the addition of abciximab reduced 30-day TVR without increasing bleeding risk, and primary stenting reduced 1-year TVR and MACE rates compared with PTCA.

Contrast-induced nephropathy after percutaneous coronary interventions in relation to chronic kidney disease and hemodynamic variables.

We previously found that contrast-induced nephropathy (CIN) complicating percutaneous coronary intervention adversely affects patients with chronic kidney disease (CKD). Therefore, we further investigated whether the predictors and outcome of CIN after percutaneous coronary intervention differ among patients with versus without CKD. Among 7,230 consecutive patients, CIN (>or=25% or >or=0.5 mg/dl increase in preprocedure serum creatinine 48 hours after the procedure) developed in 381 of 1,980 patients (19.2%) with baseline CKD (estimated glomerular filtration rate [eGFR] <60 ml/min/1.73 m(2)) and in 688 of 5,250 patients (13.1%) without CKD. Decreased eGFRs, periprocedural hypotension, higher contrast media volumes, lower baseline hematocrit, diabetes, pulmonary edema at presentation, intra-aortic balloon pump use, and ejection fraction <40% were the most significant predictors of CIN in patients with CKD. Apart from intra-aortic balloon pump use, predictors of CIN in patients without CKD were the same as mentioned, plus older age and type of contrast media. Regardless of baseline renal function, CIN correlated with longer in-hospital stay and higher rates of in-hospital complications and 1-year mortality compared with patients without CIN. By multivariate analysis, CIN was 1 of the most powerful predictors of 1-year mortality in patients with preexisting CKD (odds ratio 2.37, 95% confidence interval 1.63 to 3.44) or preserved eGFR (odds ratio 1.78; 95% confidence interval 1.22 to 2.60). Thus, regardless of the presence of CKD, baseline characteristics and periprocedural hemodynamic parameters predict CIN, and this complication is associated with worse in-hospital and 1-year outcomes.

Predictors of and outcomes of early thrombosis following balloon angioplasty versus primary stenting in acute myocardial infarction and usefulness of abciximab (the CADILLAC trial).

We sought to identify the predictors and clinical outcomes of early thrombosis after primary angioplasty and stenting for acute myocardial infarction (AMI). Little is known about the correlates and prognosis of acute and subacute thromboses after percutaneous coronary intervention (PCI) for AMI. We therefore studied the frequency, clinical determinants, and implications of early thrombosis in a large trial of patients who had primary PCI. In the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications trial, 2,082 patients who had AMI were randomized in a 2 x 2 factorial design to primary stenting or to balloon angioplasty, each with and without abciximab. Early thrombosis occurred in 19 patients (0.9%) at a median of 2 days (range 0 to 23). Maximal balloon diameter was smaller, and aneurysmal and bifurcation lesions were more prevalent in the group with early thrombosis. Early thrombosis occurred in 0.4% of patients who had been randomized to receive abciximab versus 1.5% of control patients (p <0.01) and in 0.5% of patients who had been randomized to undergo stenting versus 1.4% of those who underwent balloon angioplasty (p = 0.04). By multivariate analysis, abciximab use was an independent predictor of no thrombosis (hazard ratio 0.27, 95% confidence interval 0.09 to 0.86, p = 0.026). Within 30 days, 5.3% of patients who had early thrombosis died, 32.9% developed reinfarction, and 89.5% required repeat target vessel revascularization (including bypass surgery in 11.1%). As a result, patients who had versus those who did not have early thrombosis had markedly higher rates of major adverse cardiac events at 30 days (94.7% vs 5.0%, p <0.0001) and at 1 year (94.7% vs 16.9%, p <0.0001). Patients who develop early thrombosis after primary PCI have a very high rate of major adverse cardiac events, including death and reinfarction, and usually require repeat coronary angioplasty or surgery for management. Complex baseline angiographic morphology and smaller maximal balloon diameter are predictors of early thrombosis after primary PCI for AMI. The incidence of early thrombosis after primary angioplasty and stenting is decreased by abciximab use.

Impact of anemia on outcomes of patients undergoing percutaneous coronary interventions.

Of 6,929 consecutive patients who were treated with percutaneous coronary intervention, 1,708 (24.6%) had anemia according to criteria of the World Health Organization. Compared with patients who did not have anemia, those who did have anemia were older, more frequently women and African-American, had a smaller body mass index, and higher frequencies of cardiovascular risk factors and co-morbid conditions. Patients who had anemia compared with those who did not have anemia had significantly (p <0.0001) higher mortality rates during hospitalization (1.9% vs 0.4%) and at 1 year (12.8% vs 3.5%). After adjustment for potential confounders, baseline hematocrit remained a significant predictor of a 1-year mortality rate (hazard ratio 0.93 per 1% increase in hematocrit, 95% confidence interval 0.91 to 0.95).

A simple risk score for prediction of contrast-induced nephropathy after percutaneous coronary intervention: development and initial validation.

OBJECTIVES: We sought to develop a simple risk score of contrast-induced nephropathy (CIN) after percutaneous coronary intervention (PCI). BACKGROUND: Although several risk factors for CIN have been identified, the cumulative risk rendered by their combination is unknown. METHODS: A total of 8,357 patients were randomly assigned to a development and a validation dataset. The baseline clinical and procedural characteristics of the 5,571 patients in the development dataset were considered as candidate univariate predictors of CIN (increase >or=25% and/or >or=0.5 mg/dl in serum creatinine at 48 h after PCI vs. baseline). Multivariate logistic regression was then used to identify independent predictors of CIN with a p value <0.0001. Based on the odds ratio, eight identified variables (hypotension, intra-aortic balloon pump, congestive heart failure, chronic kidney disease, diabetes, age >75 years, anemia, and volume of contrast) were assigned a weighted integer; the sum of the integers was a total risk score for each patient. RESULTS: The overall occurrence of CIN in the development set was 13.1% (range 7.5% to 57.3% for a low [or=16] risk score, respectively); the rate of CIN increased exponentially with increasing risk score (Cochran Armitage chi-square, p < 0.0001). In the 2,786 patients of the validation dataset, the model demonstrated good discriminative power (c statistic = 0.67); the increasing risk score was again strongly associated with CIN (range 8.4% to 55.9% for a low and high risk score, respectively). CONCLUSIONS: The risk of CIN after PCI can be simply assessed using readily available information. This risk score can be used for both clinical and investigational purposes.

Impact of anemia in patients with acute myocardial infarction undergoing primary percutaneous coronary intervention: analysis from the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) Trial.

OBJECTIVES: We sought to investigate the impact of anemia in patients with acute myocardial infarction (AMI) undergoing primary percutaneous coronary intervention (PCI). BACKGROUND: The prognostic importance of anemia on primary PCI outcomes is unknown. METHODS: In the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) trial, 2,082 patients of any age with AMI within 12 h onset undergoing primary PCI were randomized to balloon angioplasty versus stenting, each +/- abciximab. Outcomes were stratified by the presence of anemia at baseline, as defined by World Health Organization criteria (hematocrit <39% for men and <36% for women). RESULTS: Anemia was present in 260 (12.8%) of 2,027 randomized patients with baseline laboratory values. Patients with versus without baseline anemia more frequently developed in-hospital hemorrhagic complications (6.2% vs. 2.4%, p = 0.002), had higher rates of blood product transfusions (13.1% vs. 3.1%, p < 0.0001), and had a prolonged (median 4.1 vs. 3.5 days, p < 0.0001) and more expensive (median costs $12,434 vs. $11,603, p = 0.002) index hospitalization. Patients with versus without anemia had strikingly higher mortality during hospitalization (4.6% vs. 1.1%, p = 0.0003), at 30 days (5.8% vs. 1.5%, p < 0.0001), and at 1 year (9.4% vs. 3.5%, p < 0.0001). The rates of disabling stroke at 30 days (0.8% vs. 0.1%, p = 0.005) and at 1 year (2.1% vs. 0.4%, p = 0.0007) were also significantly higher in patients with anemia. By multivariate analysis, anemia was an independent predictor of in-hospital mortality (hazard ratio, 3.26; p = 0.048) and one-year mortality (hazard ratio, 2.38; p = 0.016). CONCLUSIONS: Anemia at baseline in patients with AMI undergoing primary PCI is common, and is strongly associated with adverse outcomes and increased mortality.

Vascular complications associated with arteriotomy closure devices in patients undergoing percutaneous coronary procedures: a meta-analysis.

OBJECTIVES: This study was designed to assess the safety of arteriotomy closure devices (ACDs) versus mechanical compression by meta-analysis in patients undergoing percutaneous transfemoral coronary procedures. BACKGROUND: Although ACDs are widely applied for hemostasis after percutaneous endovascular procedures, their safety is controversial. METHODS: Randomized, case-control, and cohort studies comparing access-related complications using ACDs versus mechanical compression were analyzed. The primary end point was the cumulative incidence of vascular complications, including pseudoaneurysm, arteriovenous fistula, retroperitoneal hematoma, femoral artery thrombosis, surgical vascular repair, access site infection, and blood transfusion. RESULTS: A total of 30 studies involving 37,066 patients were identified. No difference in complication incidence between Angio-Seal and mechanical compression was revealed in the diagnostic (Dx) setting (odds ratio [OR] 1.08, 95% confidence interval [CI] 0.11 to 10.0) or percutaneous coronary interventions (PCI) (OR 0.86, 95% CI 0.65 to 1.12). Meta-analysis of randomized trials only showed a trend toward less complications using Angio-Seal in a PCI setting (OR 0.46, 95% CI 0.20 to 1.04; p = 0.062). No differences were observed regarding Perclose in either Dx (OR 1.51, 95% CI 0.24 to 9.47) or PCI (OR 1.21, 95% CI 0.94 to 1.54) setting. An increased risk in complication rates using VasoSeal in the PCI setting (OR 2.25, 95% CI 1.07 to 4.71) was found. The overall analysis favored mechanical compression over ACD (OR 1.34, 95% CI 1.01 to 1.79). CONCLUSIONS: In the setting of Dx angiography, the risk of access-site-related complications was similar for ACD compared with mechanical compression. In the setting of PCI, the rate of complications appeared higher with VasoSeal.

Impact of chronic kidney disease on prognosis of patients with diabetes mellitus treated with percutaneous coronary intervention.

Chronic kidney disease (CKD) is a frequent complication of diabetes mellitus. However, the role of CKD in outcomes of patients with diabetes who have undergone percutaneous coronary intervention (PCI) has not been studied specifically. Therefore, we investigated the impact of CKD on prognosis of patients with diabetes who underwent PCI. Of 1,575 diabetic patients who underwent PCI, 1,046 (66%) had preserved renal function, 492 (31%) had CKD (baseline serum creatinine >1.5 mg/dl or estimated glomerular filtration rate <60 ml/min/1.73 m(2)) without dialysis, and 37 (2.3%) were dependent on dialysis. Patients with CKD versus those without CKD had more in-hospital complications, including mortality (2.6% vs 0.5%, respectively; p <0.0001), neurologic events (3.1% vs 0.6%, p = 0.0001), and gastrointestinal bleeding (2.9% vs 0.9%, p = 0.01). Contrast-induced nephropathy after PCI (increase > or =25% and/or > or =0.5 mg/dl of serum creatinine before PCI vs 48 hours after PCI) was found in 15% of patients without CKD versus 27% of those with CKD, and de novo dialysis was instituted in 0.1% versus 3.1%, respectively. Contrast-induced nephropathy was independently predicted (all p <0.0001) by peri-PCI hypotension (odds ratio [OR] 2.62), insulin treatment (OR 1.84), and volume of contrast medium (OR 1.30). The 1-year mortality rate was strikingly higher (all p <0.0001) in patients with CKD who did not receive dialysis (16%) and those on dialysis (44%) compared with the group with preserved renal function (5%). Contrast-induced nephropathy was among the independent predictors of a 1-year mortality rate (OR 2.75, p <0.001).

Short- and long-term results after multivessel stenting in diabetic patients.

OBJECTIVES: The present study evaluated clinical outcomes in diabetic patients after multivessel stenting. BACKGROUND: Multivessel angioplasty studies have reported decreased survival in diabetic patients undergoing conventional balloon angioplasty compared with coronary artery bypass graft surgery (CABG). However, several studies have demonstrated excellent procedural success and acceptable clinical outcomes after multivessel stenting. METHODS: Multivessel stenting was performed in 689 patients with 1,639 native coronary lesions. Patients were classified into three groups according to diabetes mellitus (DM) status: 1) no DM (501 patients/1,200 lesions); 2) DM treated with oral agents (102 patients/235 lesions); and 3) DM treated with insulin (86 patients/204 lesions). RESULTS: Procedural success was high overall. In-hospital CABG was higher in diabetics treated with insulin compared with the other two groups (3.5% vs. 0.4% vs. 1.0%, p = 0.02). There were no significant differences in the incidence of in-hospital cardiac death and myocardial infarction. Diabetic patients treated with oral agents or insulin had higher one-year target lesion revascularization rates than non-diabetic patients (25% vs. 35% vs. 16%, p < 0.001). Lower one-year survival was observed in diabetic patients treated with either oral agents or insulin, compared with non-diabetic patients (85% vs. 86% vs. 95%, p < 0.001). On multivariable analysis, DM was an independent predictor of one-year mortality, myocardial infarction, and target lesion revascularization after multivessel stenting. CONCLUSIONS: Despite a high technical success rate of multivessel stenting, diabetic patients, especially those treated with insulin, have higher in-hospital CABG, higher subsequent revascularization rates, and lower one-year survival than non-diabetic patients.

Comparison of frequency of hemorrhagic stroke in patients <75 years versus > or =75 years of age among patients receiving glycoprotein IIb/IIIa inhibitors during percutaneous coronary interventions.

We identified 1,369 consecutive patients who received glycoprotein IIb/IIIa inhibitors during 1,461 stenting procedures (2,382 lesions); of these, 240 (17.5%) were aged > or =75 years (253 procedures, 430 lesions). Very elderly patients (> or =75 years) had similar in-hospital outcomes but a higher hemorrhagic stroke rate than patients aged <75 years.

Impact of symptomatic peripheral arterial disease on 1-year mortality in patients undergoing percutaneous coronary interventions.

PURPOSE: To determine the impact of symptomatic peripheral arterial disease (PAD) on clinical outcomes in patients treated with percutaneous coronary interventions (PCI). METHODS AND RESULTS: Symptomatic PAD was identified in 1969 (18.9%) of 10440 consecutive patients undergoing PCI. Patients with PAD were older, more frequently female, and had smaller body surface area and more atherosclerotic risk factors, chronic renal insufficiency, and heart failure. Patients with PAD had lower rates of procedural success (94.2% versus 96.2%, p<0.0001) and higher rates of in-hospital complications, including all-cause mortality (2.1% versus 1.1%, p=0.0002), cardiac death (1.5% versus 0.7%, p=0.0009), urgent coronary artery bypass grafting (1.9% versus 1.2%, p=0.01), recurrent ischemia (5.6% versus 2.8%, p<0.0001), re-PCI to the target lesion (2.4% versus 1.1%, p<0.0001), stroke (0.6% versus 0.3%, p=0.0344), transient ischemic attack (0.4% versus 0.1%, p=0.01), femoral hematoma (10.3% versus 8.5%, p=0.01), retroperitoneal hematoma (0.8% versus 0.3%, p=0.009), limb ischemia (3.0% versus 0.7%, p<0.0001), gastrointestinal bleeding (1.9% versus 0.9%, p<0.0001), and blood transfusion (10.1% versus 5.2%, p<0.0001). At 1-year follow-up, patients with PAD had a higher mortality rate (13.6% versus 5.2%, p<0.0001), a higher rate of myocardial infarction (8.3% versus 6.5%, p=0.008), and also more target lesion (21.2% versus 19.8%, p=0.02) or target vessel revascularization (24.6% versus 21.2%, p=0.002). By multivariate analysis, PAD was an independent predictor of 1-year mortality (odds ratio 1.71, 95% confidence interval 1.42 to 2.07, p<0.0001). CONCLUSIONS: Nearly a fifth of patients undergoing PCI have symptomatic PAD. The presence of PAD is associated with lower rates of procedural success, higher rates of in-hospital and 1-year adverse events, and is independently associated with increased 1-year mortality.

Increased CK-MB release is a "trade-off" for optimal stent implantation: an intravascular ultrasound study.

OBJECTIVES: We sought to determine the impact of aggressive stent expansion on creatine kinase-MB isoenzyme (CK-MB) release and clinical restenosis. BACKGROUND: Elevation of CK-MB after percutaneous coronary interventions has been associated with late mortality. METHODS: We identified 989 consecutive patients who underwent intravascular ultrasound-guided stenting of 1,015 coronary lesions. Patients were divided into three groups according to stent expansion, defined as the ratio of final lumen over the reference lumen cross-sectional areas: Group 1 (ratio <70%, n = 117 patients with 126 lesions); Group 2 (ratio 70% to 100%, n = 551 patients with 562 lesions); Group 3 (ratio >100%, n = 321 patients with 327 lesions). RESULTS: The peak CK-MB values increased significantly with increasing stent expansion: CK-MB = 3 to 5x normal occurred 16%, 18%, and 25% in Groups 1, 2, and 3, respectively, p = 0.02; CK-MB >5 times normal occurred 9%, 13%, and 16% respectively, p = 0.02. Conversely, at one year follow-up there was a stepwise decrease in target lesion revascularization (11% vs. 19% and 17%, respectively, p = 0.04) and major adverse cardiac events with increasing stent expansion. In addition, there was a trend toward lower mortality in Group 3 (9% vs. 4.4% vs. 4.0%, p = 0.07). CONCLUSIONS: Intravascular ultrasound-guided stent overexpansion (final lumen greater than reference lumen cross-sectional area) is accompanied by a higher periprocedural CK-MB release but a lower target lesion revascularization and a trend toward lower mortality at one year. Increased periprocedural CK-MB release appears as a trade-off for optimal stent implantation and lower clinical restenosis.

Comparison of effect of glycoprotein IIb/IIIa inhibitors during percutaneous coronary interventions on risk of hemorrhagic stroke in patients >or=75 years of age versus those <75 years of age.

Of 1,369 consecutive patients who underwent stent-assisted coronary angioplasty and who were treated with glycoprotein IIb/IIIa inhibitors during these procedures, 17.5% were >or=75 years of age. Compared with patients <75 years old, those >or=75 years of age had similar procedural and in-hospital outcomes but significantly higher rates of hemorrhagic stroke (0.08% vs 1.2%, p <0.001).

Safety of an aspirin-alone regimen after intracoronary stenting with a heparin-coated stent: final results of the HOPE (HEPACOAT and an Antithrombotic Regimen of Aspirin Alone) study.

BACKGROUND: Stent thrombosis is an infrequent complication of intracoronary stenting that often has devastating clinical consequences. This study assesses the additional benefit of heparin coating with the BX VELOCITY Balloon-Expandable Stent with HEPACOAT, Carmeda end-point attached heparin (HEPACOAT) in patients with de novo or restenotic native coronary artery lesions treated with aspirin monotherapy after optimal stenting. METHODS AND RESULTS: This was a multicenter, prospective, nonrandomized, pilot study. Two hundred patients (69% men; mean age, 64.1+/-11.2 years) meeting the eligibility criteria were treated with the HEPACOAT stent and aspirin alone after stenting. Any other antiplatelet or anticoagulation therapy was not permitted. Procedural success was achieved in all patients. There were 3 postprocedural non-Q-wave myocardial infarctions. The primary end point of stent thrombosis at 30 days occurred in 2 of 200 patients (1%): in one after blunt chest trauma and in the other in the setting of essential thrombocytosis. Major adverse cardiac events (death, myocardial infarction, target lesion revascularization, and coronary artery bypass grafting) were observed at 30 days in 5 of 200 (2.5%) patients. CONCLUSIONS: The BX VELOCITY stent with HEPACOAT and aspirin alone after the procedure was safe in select patients with de novo or restenotic lesions in native coronary arteries. Heparin coating provides additional protection against stent thrombosis.

Radiocontrast nephropathy: identifying the high-risk patient and the implications of exacerbating renal function.

Radiographic procedures using contrast media are widely performed throughout the world. This necessitates physicians' awareness of radiocontrast nephropathy-the disorder that develops as a result of exposure to contrast agents. Although in the general population the risk of radiocontrast nephropathy is rather low, it may be very high in selected subsets of patients. This article focuses on the incidence, pathogenesis, risk factors, and prognosis of radiocontrast nephropathy and provides important insights on its prevention.

Abciximab attenuates coronary microvascular endothelial dysfunction after coronary stenting.

BACKGROUND: Platelet glycoprotein IIb/IIIa receptor blockade with abciximab decreases ischemic events after percutaneous coronary intervention (PCI); however, the mechanism of this benefit has not been fully elucidated. The present study was designed to assess endothelium-dependent vasomotion after coronary stenting and to determine if abciximab alters this response. METHODS AND RESULTS: The study group consisted of 48 patients (59+/-10 years of age) with discrete coronary stenoses who underwent stenting alone (n=28) or stenting plus abciximab (n=20). A control group consisted of 31 additional patients who had vasomotor testing on a non-PCI vessel. Coronary blood flow (CBF) was measured (0.014-inch Doppler wire) 30 minutes after uncomplicated PCI and in response to the intracoronary infusion of acetylcholine (Ach) (10(-7), 10(-6) mol/L Ach) and adenosine (24 microg). Ach-mediated increase in CBF was impaired after stent insertion when compared with the control group (41+/-52% versus 70+/-48%; P<0.05). The stenting plus abciximab group demonstrated a superior CBF response to Ach compared with the stenting alone group (83+/-93% versus 41+/-52%; P<0.05), with no difference between groups in the peak flow or percent change in flow to adenosine. By multivariate analysis, concomitant administration of abciximab was strongly predictive of the change in CBF to Ach (P<0.005). CONCLUSIONS: Abciximab preserves the CBF response to Ach after coronary stenting. The preservation of microvascular endothelial function may help explain the beneficial clinical effect of this agent in patients undergoing PCI.