Sue Apple

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) ≤ 1.2 mg/dl and no history of renal insufficiency. One‐year follow‐up was obtained by mail or telephone. There were 5,967 consecutive patients who met the inclusion criteria. Of these, 208 (3.5%) developed DRF (an increase in 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. Cathet Cardiovasc Intervent 2003;59:338–343.

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 mm2, 3.3±2.2 mm, 21±27 mm3, 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 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 institutions 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. Cathet Cardiovasc Intervent 2003;59:436–441.

A Systematic Approach to Pacemaker Assessment

Despite the increasing use of pacemaker therapy, assessment of pacemaker function and electrocardiogram (ECG) interpretation continue to challenge even experienced critical care nurses. Accurate assessment of pacemaker function is essential in the evaluation of patients, especially patients with symptoms that may be related to pacemaker malfunction such as syncope or palpitations. This article will review pacing concepts and pacing system components. A systematic approach to ECG interpretation will be presented that can be used in a variety of clinical settings.