Gender differences in the treatment and outcome of acute myocardial infarction

Percutaneous coronary intervention and adjunctive pharmacotherapy in women: a statement for healthcare professionals from the American Heart Association

More than 1.2 million percutaneous coronary interventions are performed annually in the United States, with only an estimated 33% performed in women, despite the established benefits of percutaneous coronary intervention and adjunctive pharmacotherapy in reducing fatal and nonfatal ischemic complications in acute myocardial infarction and high-risk acute coronary syndromes. This statement reviews sex-specific data on the safety and efficacy of contemporary interventional therapies in women.

Heparin-coated stent placement for the treatment of stenoses in small coronary arteries of symptomatic patients

BACKGROUND

The role of stents, especially of heparin-coated stents for the treatment of stenoses in small coronary arteries, is still unclear. Therefore, we performed this prospective, randomized trial to evaluate the angiographic and clinical outcome after treatment of stenoses in small coronary arteries (2.0 to 2.6 mm) of symptomatic patients.

METHODS AND RESULTS

We randomly assigned 588 patients to angioplasty (n=195), bare stenting (n=196), or heparin-coated stenting (n=197). The primary end point was minimal lumen diameter (MLD) at 6 months. With comparable baseline parameters, the two stent arms showed a larger postinterventional MLD, larger acute gain, and smaller residual percent diameter stenosis, although a residual stenosis of 12+/-16% was achieved in the angioplasty arm, including a 27% crossover rate to stenting. Eighty percent of patients had follow-up angiography, which documented a borderline significantly larger MLD and smaller percent diameter stenosis for the two stent groups (1.34+/-0.48 mm and 42+/-20% after angioplasty, 1.47+/-0.48 mm and 36+/-20% after bare stenting, and 1.45+/-0.54 mm and 38+/-23% after heparin-coated stenting; P=0.049 and P=0.038, respectively), but restenosis rates were not different (32%, 25%, and 30%). Thrombotic events occurred in 1.0% after angioplasty and 0.5% after bare or heparin-coated stenting. Survival without myocardial infarction or target vessel revascularization at 250 days was 84.6% (angioplasty), 88.3% (bare stenting), and 88.3% (heparin-coated stenting; log-rank P=0.39).

CONCLUSION

Compared with angioplasty with provisional stenting, bare and heparin-coated stenting confer superior angiographic results and a nonsignificant 24% reduction in clinical events, with no difference between bare and heparin-coated stenting in the treatment of stenoses in small coronary arteries.

Results of Prevention of REStenosis with Tranilast and its Outcomes (PRESTO) trial

BACKGROUND

Restenosis after percutaneous coronary intervention (PCI) is a major problem affecting 15% to 30% of patients after stent placement. No oral agent has shown a beneficial effect on restenosis or on associated major adverse cardiovascular events. In limited trials, the oral agent tranilast has been shown to decrease the frequency of angiographic restenosis after PCI.

METHODS AND RESULTS

In this double-blind, randomized, placebo-controlled trial of tranilast (300 and 450 mg BID for 1 or 3 months), 11 484 patients were enrolled. Enrollment and drug were initiated within 4 hours after successful PCI of at least 1 vessel. The primary end point was the first occurrence of death, myocardial infarction, or ischemia-driven target vessel revascularization within 9 months and was 15.8% in the placebo group and 15.5% to 16.1% in the tranilast groups (P=0.77 to 0.81). Myocardial infarction was the only component of major adverse cardiovascular events to show some evidence of a reduction with tranilast (450 mg BID for 3 months): 1.1% versus 1.8% with placebo (P=0.061 for intent-to-treat population). The primary reason for not completing treatment was > or =1 hepatic laboratory test abnormality (11.4% versus 0.2% with placebo, P<0.01). In the angiographic substudy composed of 2018 patients, minimal lumen diameter (MLD) was measured by quantitative coronary angiography. At follow-up, MLD was 1.76+/-0.77 mm in the placebo group, which was not different from MLD in the tranilast groups (1.72 to 1.78+/-0.76 to 80 mm, P=0.49 to 0.89). In a subset of these patients (n=1107), intravascular ultrasound was performed at follow-up. Plaque volume was not different between the placebo and tranilast groups (39.3 versus 37.5 to 46.1 mm(3), respectively; P=0.16 to 0.72).

CONCLUSIONS

Tranilast does not improve the quantitative measures of restenosis (angiographic and intravascular ultrasound) or its clinical sequelae.

Stent placement compared with balloon angioplasty for small coronary arteries: in-hospital and 6-month clinical and angiographic results

BACKGROUND

Stenting has been demonstrated to be superior to balloon angioplasty in de novo focal lesions located in large native vessels. However, in small vessels, the benefit of stenting remains questionable.

METHODS AND RESULTS

A total of 381 symptomatic patients with de novo focal lesion located on a small coronary segment vessel (<3 mm) were randomly assigned to either stent implantation (192 patients; 197 lesions) or standard balloon angioplasty (189 patients; 198 lesions). The primary end point was the angiographic restenosis rate at 6 months, as determined by quantitative coronary angiography. On intention-to-treat analysis, angiographic success rate and major adverse cardiac events were comparable: 97.9% and 4.6% versus 93.9% and 5.8% in the stent group and the balloon group, respectively. After the procedure, a larger acute gain was achieved with stent placement (1.35+/-0.45 versus 0.94+/-0.47 mm, P=0.0001), resulting in a larger minimal lumen diameter (2.06+/-0.42 versus 1.70+/-0.46 mm, P=0.0001). At follow-up (obtained in 91% of patients), angiographic restenosis rate was 21% in the stent group versus 47% in the balloon group (P=0.0001), a risk reduction of 55%. Repeat target lesion revascularization was less frequent in the stent group (13% versus 25%, P=0.0006).

CONCLUSIONS

Elective stent placement in small coronary arteries with focal de novo lesions is safe and associated with a marked reduction in restenosis rate and subsequent target lesion revascularization rate at 6 months.

Local delivery of enoxaparin to decrease restenosis after stenting: results of initial multicenter trial: Polish-American Local Lovenox NIR Assessment study (The POLONIA study)

BACKGROUND

Enoxaparin inhibits smooth muscle cell proliferation in experimental models. Intimal hyperplasia has been found to be the principal cause of restenosis after coronary stent implantation. We sought to determine whether the intramural delivery of enoxaparin before stenting of de novo lesions decreases restenosis.

METHODS AND RESULTS

One hundred patients who were undergoing stenting were randomly assigned to either local administration of enoxaparin during predilation with reduced systemic heparinization or stenting with standard, systemic heparinization. All patients were treated with the same type of stent (NIR). The primary study end point was late luminal loss. The secondary end points were major adverse cardiac events, target lesion revascularization, and angiographic restenosis at 6 months. Angiographic follow-up at 6 months was completed in all except 1 patient. Late luminal loss was reduced to 0.76+/-0.42 mm in the local enoxaparin delivery group versus 1. 07+/-0.49 mm in the systemic heparinization group (P:<0.001). Restenosis, using a binary definition, occurred in 10% of patients in the enoxaparin group and in 24% of patients in the systemic heparinization group (P:<0.05). Target lesion revascularization rates occurred in 8% of the enoxaparin group and 22% of the systemic heparinization group (P:<0.05). There were no deaths and no emergent CABGs were performed. The only subacute stent closure and non-Q-wave infarction occurred in a patient assigned to the systemic heparinization group.

CONCLUSIONS

This is the first prospective randomized trial in which the local delivery of a drug, enoxaparin, resulted in significant reduction in late luminal loss and restenosis after stent implantation in de novo coronary lesions.

Are patients with renal failure good candidates for percutaneous coronary revascularization in the new device era?

BACKGROUND

Patients with end-stage renal disease undergoing conventional balloon angioplasty have reduced procedural success and increased complication rates. This study was designed to determine the immediate and long-term outcomes of patients with varying degrees of renal failure undergoing percutaneous coronary intervention in the current device era.

METHODS AND RESULTS

We compared the immediate and long-term outcomes of 362 renal failure patients (creatinine >1.5 mg/dL) with those of 2972 patients with normal renal function who underwent percutaneous coronary intervention between 1994 and 1997. Patients with renal failure were older and had more associated comorbidities. They had reduced procedural success (89.5% versus 92.9%, P:=0.007) and greater in-hospital combined major event (death, Q-wave myocardial infarction, emergent CABG; 10.8% versus 1.8%; P:<0.0001) rates. Renal failure was an independent predictor of major adverse cardiac events (MACEs) (OR, 3.41; 95% CI, 1.84 to 6.22; P:<0.00001). Logistic regression analysis identified shock, peripheral vascular disease, balloon angioplasty strategy, and unstable angina as independent predictors of in-hospital MACEs in the renal group. Compared with 362 age- and sex-matched patients selected from the control group, patients with renal failure had a lower survival rate (27.7% versus 6.1%, P:<0.0001) and a greater MACE rate (51% versus 33%, P:<0.001) at long-term follow-up. Cox regression analysis identified age and PTCA strategy as independent predictors of long-term MACEs in the renal group. Finally, within the renal failure population, the dialysis and nondialysis patients experienced remarkably similar immediate and long-term outcomes.

CONCLUSIONS

Although patients with renal failure can be treated with a high procedural success rate in the new device era, they have an increased rate of major events both in hospital and at long-term follow-up. Nevertheless, utilization of stenting and debulking techniques improves immediate and long-term outcomes.

A randomized trial comparing stenting with balloon angioplasty in small vessels in patients with symptomatic coronary artery disease. ISAR-SMART Study Investigators. Intracoronary Stenting or Angioplasty for Restenosis Reduction in Small Arteries

BACKGROUND

More than 30% of the lesions currently treated with interventional approaches are situated in vessels smaller in size than those representing an established indication for stenting. The objective of this randomized trial was to assess whether compared with PTCA, stenting of small coronary vessels is associated with a reduction of restenosis.

METHODS AND RESULTS

Patients with symptomatic coronary artery disease with lesions situated in native coronary vessels between 2 and 2.8 mm in size were randomly assigned to be treated with either stenting (n=204) or PTCA (n=200). Adjunct therapy consisted of abciximab, ticlopidine, and aspirin. Repeat angiography at 6-month follow-up was performed in 83% of the patients. The primary end point of the study was the incidence of angiographic restenosis (>/=50% diameter stenosis) at follow-up; adverse clinical events, such as death, myocardial infarction, stroke, or target vessel revascularization, were assessed as secondary end points. After 7 months, there were no significant differences in the infarct-free survival rates between the 2 study groups: 96.6% for stent patients, and 97.0% for PTCA patients (P:=0. 80). Target vessel revascularization was needed in 20.1% of the stent patients and 16.5% of the PTCA patients (P:=0.35). The primary end point of angiographic restenosis was found in 35.7% of the stent patients and 37.4% of the PTCA patients (P:=0.74). The net lumen gain observed at follow-up was identical (0.76+/-0.78 in the stent group versus 0.76+/-0.63 mm in the PTCA group, P:=0.93).

CONCLUSIONS

Stenting and PTCA are associated with equally favorable results when used for treating lesions in small coronary vessels.

Reference chart derived from post-stent-implantation intravascular ultrasound predictors of 6-month expected restenosis on quantitative coronary angiography

BACKGROUND

Intravascular ultrasound (IVUS)-guided stent implantation and the availability of a reference chart to predict the expected in-stent restenosis rate based on operator-dependent IVUS parameters may interactively facilitate optimal stent placement. The use of IVUS guidance protects against undue risks of dissection or rupture.

METHODS AND RESULTS

IVUS-determined post-stent-implantation predictors of 6-month in-stent restenosis on quantitative coronary angiography (QCA) were identified by logistic regression analysis. These predictors were used to construct a reference chart that predicts the expected 6-month QCA restenosis rate. IVUS and QCA data were obtained from 3 registries (MUSIC [Multicenter Ultrasound Stenting in Coronaries study], WEST-II [West European Stent Trial II], and ESSEX [European Scimed Stent EXperience]) and 2 randomized in-stent restenosis trials (ERASER [Evaluation of ReoPro And Stenting to Eliminate Restenosis] and TRAPIST [TRApidil vs placebo to Prevent In-STent intimal hyperplasia]). In-stent restenosis was defined as luminal diameter stenosis >50% by QCA. IVUS predictors were minimum and mean in-stent area, stent length, and in-stent diameter. Multiple models were constructed with multivariate logistic regression analysis. The model containing minimum in-stent area and stent length best fit the Hosmer-Lemeshow goodness-of-fit test. This model was used to construct a reference chart to calculate the expected 6-month restenosis rate.

CONCLUSIONS

The expected 6-month in-stent restenosis rate after stent implantation for short lesions in relatively large vessels can be predicted by use of in-stent minimal area (which is inversely related to restenosis) and stent length (which is directly related to restenosis), both of which can be read from a simple reference chart.

Vessel size and long-term outcome after coronary stent placement

BACKGROUND

The role of coronary stenting in the treatment of patients with small vessels is not well defined. The purpose of this study was to investigate the influence of vessel size on long-term clinical and angiographic outcome after coronary stent placement.

METHODS AND RESULTS

The study comprised 2602 patients with successful stent implantation for symptomatic coronary artery disease. Patients were subdivided into 3 equally sized groups (tertiles) according to vessel size, with respective ranges of <2.8, 2.8 to 3.2, and >3.2 mm. Event-free survival at 1 year was 69.5% in the group with smaller vessels, 77.5% in the second group, and 81% in the group with larger vessels (P<0.001). Late lumen loss was similar between the 3 groups (1.12+/-0.73, 1.12+/-0.79, and 1.09+/-0. 88 mm, respectively). Angiographic restenosis rate was significantly higher in the small-vessel group (38.6%, 28.4%, and 20.4% in groups 1, 2, and 3, respectively; P<0.001). The analysis identified subgroups with different risk for restenosis even among patients with small vessels. Within this group, the restenosis rate may be as low as 29.6% in patients without additional risk factors and as high as 53.5% in patients with diabetes and complex lesions.

CONCLUSIONS

Patients with small vessels present a higher risk for an adverse outcome after coronary stent placement because of a higher incidence of restenosis. However, the unusually high risk for restenosis is confined to those patients with small vessels who have concomitant risk factors such as diabetes and complex lesions.