Preprocedure hyperglycemia is more strongly associated with restenosis in diabetic patients after percutaneous coronary intervention than is hemoglobin A1C.

BACKGROUND: Although more frequent in diabetic patients, restenosis after percutaneous coronary intervention (PCI) is less common in those with good glycemic control. High circulating insulin levels may also be associated with more frequent restenosis. METHODS: Fasting blood samples were obtained from 162 diabetic patients immediately prior to the PCI and analyzed for glucose, hemoglobin A1C, and insulin. Nine-month follow-up information was obtained in 145 (89.5%) patients. Target vessel revascularization (TVR) was the surrogate for restenosis. RESULTS: Patients were divided into quartiles with regard to their blood levels. Insulin, calculated insulin resistance, and hemoglobin A1C were not associated with increased TVR rates. Glucose level was significantly associated (P=.02). Patients in the two lower quartiles (glucose < or = 128 mg/dl) had a 9-month TVR rate of 12.7% while those in the two higher quartiles (>128 mg/dl) had a rate of 33.8% (P=.005). Level of glucose was independent of hemoglobin A1C. In patients whose A1C level was < or = 7%, the TVR rate was greater in those with a glucose level >128 mg/dl (39.1% vs. 10.6%, P=.009). Similarly, in patients with a hemoglobin A1C level >7%, the TVR rate was lower in patients with a glucose level < or = 128 mg/dl, but this difference did not reach statistical significance (16.6% vs. 31.3%, P=.3). CONCLUSIONS: Hemoglobin A1C, insulin, and insulin resistance at the time of the PCI are not associated with restenosis. Periprocedural hyperglycemia may promote restenosis in diabetics.

Background incidence of late malapposition after bare-metal stent implantation.

BACKGROUND: Late stent malapposition has been reported to be an abnormal finding after vascular brachytherapy and, possibly, implantation of drug-eluting stents. It can only be detected if intravascular ultrasound (IVUS) is performed at follow-up. However, the "background" frequency of late stent malapposition after bare-metal stent implantation is not known. METHODS AND RESULTS: We studied 206 patients with native artery lesions who had tubular-slotted bare-metal stent implantation and who had IVUS performed at index and after 6+/-3 months of follow-up. There were 9 patients (4.4%) with late malapposition, which is separation of at least 1 stent strut from the arterial wall intima that does not overlap a side-branch, with evidence of blood flow (speckling) behind the strut, and where the immediate postimplantation IVUS revealed complete apposition of the stent to the vessel wall. The location of late malapposition was the stent edge in 8 of 9 patients. The maximum area, length, volume, and arc of late malapposition measured 3.1+/-2.4 mm(2), 3.3+/-2.2 mm, 21+/-27 mm(3), and 110+/-61 degrees, respectively. There was an increase in external elastic membrane (EEM) area (20.7+/-4.9 to 26.9+/-4.2 mm, P=0.0021) and plaque area (10.1+/-3.7 to 14.8+/-3.6 mm, P=0.0022); however, the increase in EEM was greater than the increase in plaque. The area of late malapposition correlated directly with the increase in EEM area (r=0.75, P=0.0205). CONCLUSION: Late malapposition occurs in 4% to 5% of slotted-tube bare-metal stents, usually at stent edges. The main cause is positive remodeling out of proportion to the increase in peri-stent intimal hyperplasia.

Clinical, angiographic, and intravascular ultrasound characteristics of early saphenous vein graft failure.

OBJECTIVES: We sought to examine saphenous vein graft (SVG) lesions that fail within the first year after operation. BACKGROUND: Saphenous vein grafts remain patent for approximately 10 years; however, up to 15% to 20% of SVGs become occluded within the first year. METHODS: We studied 100 patients who underwent percutaneous coronary intervention (PCI) for early (<1 year post-implantation) SVG failure lesions and compared them with a diabetes- and hypercholesterolemia-matched cohort of late SVG failures (>1 year). Coronary angiography and intravascular ultrasound images were analyzed. RESULTS: The majority of patients in both groups were males who presented with unstable angina; 36% were diabetic. Graft ages were 6.0 +/- 2.9 months and 105.4 +/- 50.8 months, respectively. The early SVG failure lesion location was more often ostial or proximal (62% vs. 42%, respectively). Early SVG failures were angiographically smaller than late failures (reference: 2.47 +/- 0.86 mm vs. 3.26 +/- 0.83 mm, p < 0.001) but had similar lesion lengths. Intravascular ultrasound showed that early failure lesions had smaller proximal and distal reference lumen areas (7.3 +/- 6.8 mm2 vs. 10.6 +/- 3.8 mm2, p = 0.026) and greater reference plaque burden than late failures (52.3% vs. 36.1%, p < 0.001). After PCI, 20.6% of early and 30.6% of late failure lesions had creatine kinase-myocardial band (CK-MB) greater than twice normal. CONCLUSIONS: Early SVG failure is mostly proximal or ostial, lesions appear focal, and early SVGs appear smaller than late SVGs. Intravascular ultrasound shows significant reference segment plaque burden, suggesting more severe, diffuse SVG disease.

Causes of acute renal dysfunction after percutaneous coronary intervention and comparison of late mortality rates with postprocedure rise of creatine kinase-MB versus rise of serum creatinine.

Increases in both serum creatinine and creatine kinase-MB (CK-MB) after percutaneous coronary intervention are associated with increased risk for late adverse cardiovascular events. In 5,397 patients, the strength of the association of each with late events and the risk factors for each of these markers were compared. A postprocedural increase in creatinine was a more powerful predictor of late mortality than an increase in CK-MB. Risk factors for an increase in creatinine are similar to those for contrast-induced nephropathy, suggesting that vulnerability to such injury may identify patients with increased risk for late mortality.

The importance of gender on coronary artery size: in-vivo assessment by intravascular ultrasound.

BACKGROUND: It remains controversial whether women have smaller coronary arteries than men because of a gender-specific trait, or whether the observed differences are primarily due to a difference in body size. Intravascular ultrasound (IVUS), with its ability to provide unique coronary images that allow precise measurement of arterial size in vivo, is ideally suited to address this issue. HYPOTHESIS: Female gender, independent of body size, is associated with smaller coronary artery size as measured by intracoronary ultrasound. METHODS: Intravascular ultrasound images of normal left main arteries were identified retrospectively from a single center database. Associations between demographic and clinical characteristics (including body size) and left main coronary dimensions were assessed with univariant and multivariate regression analyses. RESULTS: We identified 257 completely normal left main arteries. Mean left main arterial areas were smaller in women than in men (17.2 vs. 20.6 mm2, p < 0.001), as were mean luminal areas (14.0 vs. 16.7 mm2, p < 0.001). By multiple regression analysis, the independent predictors of left main lumen were body surface area (p < 0.001) and gender (p = 0. 003). CONCLUSIONS: Body surface area and gender are both independent predictors of coronary artery size, although body size has a greater influence than gender.

Percutaneous coronary intervention-associated nephropathy foreshadows increased risk of late adverse events in patients with normal baseline serum creatinine.

In patients with chronic renal insufficiency, further decline in renal function (DRF) after percutaneous coronary intervention (PCI) is accompanied not only by adverse in-hospital events but also by increased risk of mortality and myocardial infarction at 1 year. This analysis was undertaken to determine if patients with normal renal function who develop DRF after PCI have a comparable increase in risk of death and myocardial infarction at 1 year, and whether this risk is independent of in-hospital complications (death, myocardial infarction, urgent coronary artery bypass grafting). We performed a retrospective analysis of all patients from a single center who underwent successful PCI with no major in-hospital complications who had pre-PCI serum creatinine (SCr) /= 50% of baseline). They were more likely to be older, female, non-Caucasian, diabetic and/or hypertensive. They reported more prior cerebral or peripheral vascular events. They had undergone more complex PCI and were exposed to more radiographic contrast than the 96.5% who did not develop DRF. After adjustment for baseline variables, DRF remained an independent predictor of 1-year mortality, myocardial infarction, and target vessel revascularization. In patients without prior renal impairment, DRF post-PCI is rare but is associated with an increased risk of late adverse cardiac events similar to that in chronic renal insufficiency patients.

Clinical outcomes following stent implantation in internal mammary artery grafts.

We evaluated our experience with percutaneous coronary intervention (PCI) of internal mammary artery (IMA) grafts. From the institution's database we identified 288 patients with 311 IMA lesions. Of these, 82 (26.4%) had stents placed during PCI. Angiographic success was 92%. Mortality at 1 month was 1.7%, myocardial infarction (MI) 15.7%, and target lesion revascularization (TLR) 0.4%. Cumulative 1-year event rates were mortality 6.4%, MI 20.4%, and TLR 8.0%. TLR rates were significantly higher in the stented lesions than lesions treated with angioplasty alone (19.2% vs. 4.9%; P = 0.004). The higher TLR rate in stented lesions was most apparent at the anastomotic site (25.0% vs. 4.2%; P = 0.006). Percutaneous revascularization of IMA grafts can be performed safely with high procedural success and excellent short- and long-term results. Stenting, particularly at the anastomotic site, was associated with significantly greater rates of TLR than angioplasty alone.