To evaluate the prevalence of clinically significant renal artery stenosis (RAS) in patients referred for coronary angiography, we analyzed data on 2,439 consecutive patients. Patients underwent selective renal angiography in conjunction with coronary angiography if refractory hypertension (blood pressure > 140/90 on two drugs) or flash pulmonary edema was present. A total of 1,089 renal arteries of 534 patients were evaluated. Twelve percent (137/1,089) of the renal arteries in 19% (101/534) of patients had > 70% diameter stenosis in at least one vessel. Bilateral renal artery stenosis was present in 26% (26/101) of patients. One hundred and thirty-two of the 137 vessels underwent stent revascularization due to clinical renovascular hypertension. Acute clinical success (< 20% diameter stenosis without death or urgent surgery) was 98% (99/101). Due to high prevalence and effective available treatment, we recommend routine screening for RAS in all patients with refractory hypertension referred for coronary angiography.

Coronary and peripheral intervention requires intraprocedural anticoagulation to prevent intraluminal thrombosis. Traditionally, unfractionated heparin (UFH) is administered during the procedure to achieve activated clotting time (ACT) of 300 to 400 seconds. When the intravenous IIb/IIIa antagonists are also used, the recommended ACT is 250 to 300 seconds because higher anticoagulation (ACT, 300-400 seconds) is accompanied by an unacceptable bleeding complication rate without added benefits. Because low molecular weight heparin has a more predictable anticoagulant effect and a higher anti-factor Xa/anti-factor IIa ratio, allows better bioavailability, is resistant to inhibition by activated platelets, and does not require routine monitoring using ACT, its use for intraprocedural anticoagulation (instead of UFH) has been an area of increasing interest. The safety and efficacy of coadministration of low molecular weight heparin with IIb/IIIa antagonists have not been adequately evaluated. We report a study of prospective evaluation of the safety and efficacy of combined use of intravenous enoxaparin and intravenous eptifibatide during nonemergent coronary and peripheral vascular intervention in 93 consecutive procedures performed on 56 patients. The procedural success rate was 99% (92/93 procedures), the acute clinical success rate was 98% (54/55 patients), the major bleeding complication rate was 2% (1/56 patients), and the vascular complication rate was 0.0%. In conclusion, the use of intravenous enoxaparin in conjunction with intravenous eptifibatide during nonemergent coronary and peripheral vascular intervention is safe and effective and eliminates the need for routine measurement of ACT during the procedure.

Occlusion of lower extremity vascular bypass grafts results in acute limb-threatening ischemia. The underlying cause of graft failure generally is distal anastomosis stenosis, and relief of culprit stenosis is a required to maintain long-term patency. Of the three thrombolytic agents used for prolonged infusion to accomplish fibrinolysis, streptokinase was the first to be used and is limited owing to the antigenicity that precludes repeated use. Urokinase had been the mainstay of thrombolytic therapy until it was withdrawn by the U.S. Food and Drug Administration in 1999 because of the potential of transmission of infectious agents during its manufacturing process. Recombinant tissue plasminogen activator (rt-PA) has not been studied adequately to assess safety and efficacy, and there are no standardized dosing guidelines. We report our experience with six patients presenting with acute limb-threatening ischemia attributable to thrombosis of synthetic lower extremity bypass grafts. After thrombolysis using rt-PA (mean bolus dose, 12.2 +/- 3.6 mg; range, 6-15 mg administered over 5 minutes followed by infusion at 2 mg/h for 15.6 +/- 6.4 hours; total dose, 51 +/- 16 mg), successful thrombolysis was achieved in 84% of the patients. The primary patency rate was 75% and the secondary patency rate 100% at 16 weeks. One patient underwent amputation owing to unsuccessful thrombolysis. No major bleeding or vascular complications occurred. We conclude that intra-arterial thrombolysis using rt-PA is a safe and effective therapy for patients with thrombotic occlusion of synthetic lower extremity bypass grafts presenting with acute limb-threatening ischemia and allows a high rate of secondary patency, avoiding amputation.