Renal Artery Stent Placement: Utility in Lesions Difficult to Treat With Balloon Angioplasty

AbstractObjectives. We assessed the safety and efficacy of stent placement in patients with poorly controlled hypertension and renal artery stenoses, which are difficult to treat with balloon angioplasty alone.Background. Preliminary experience with stent placement suggests improved results over balloon angioplasty alone in patients with atherosclerotic renal artery stenosis.Methods. Balloon-expandable stents were placed in 100 consecutive patients (133 renal arteries) with hypertension and renal artery stenosis. Sixty-seven of the patients had unilateral renal artery stenosis treated and 33 had bilateral renal artery stenoses treated with stents placed in both renal arteries.Results. Angiographic success, as determined by quantitative angiography, was obtained in 132 (99%) of 133 lesions. Early clinical success was achieved in 76% of the patients. Six months after stent placement, the systolic blood pressure was reduced from 173 ± 25 to 147 ± 23 mm Hg (p < 0.001); the diastolic pressure from 88 ± 17 to 76 ± 12 mm Hg (p < 0.001); and the mean number of antihypertensive medications per patient from 2.6 ± 1 to 2.0 ± 0.9 (p < 0.001). Angiographic follow-up at a mean of 8.7 ± 5.0 months in 67 patients revealed restenosis (>50% diameter narrowing) in 15 (19%) of 80 stented vessels.Conclusions. Renal artery stenting is an effective treatment for renovascular hypertension, with a low angiographic restenosis rate. Stent placement appears to be a very attractive therapy in patients with lesions difficult to treat with balloon angioplasty such as renal aorto-ostial lesions and restenotic lesions, as well as after a suboptimal balloon angioplasty result

A Laurentian provenance for the Dalradian rocks of north Mayo, Ireland, and evidence for an original basement–cover contact with the underlying Annagh Gneiss Complex

<p>Metasediments of the early Dalradian Grampian Group (Erris Group) and probable equivalents (Inishkea Division) structurally overlie Palaeoproterozoic to Neoproterozoic Annagh Gneiss Complex orthogneisses in NW Mayo, Ireland. Sm–Nd isotopic data suggest a Palaeoproterozoic source for the metasediments. K-feldspar and granitoid clasts from the Doonamo Formation, Erris Group, record U–Pb zircon ages of <em>c</em>. 1740 Ma and <em>c</em>. 980 Ma, respectively. These ages are within error of the <em>c</em>. 1730–1750 Ma Mullet gneisses and <em>c</em>. 990 Ma Grenvillian migmatitic leucosomes in the underlying Annagh Gneiss Complex. U–Pb detrital zircon data reveal that the Erris Group was deposited after <em>c</em>. 955 Ma, with predominant input from <em>c</em>. 1640, <em>c</em>. 1500 and <em>c</em>. 990 Ma interpreted Laurentian sources (Labradorian, Pinwarian and Grenvillian terranes, respectively). Limited detrital zircon data from the Inishkea Division yield similarly aged detritus and a tentative maximum depositional age of <em>c</em>. 1005 Ma. Correlation of both sequences with the Scottish Dalradian Grampian Group is considered valid based on detrital zircon U–Pb and whole-rock Sm–Nd data. The clast ages support the hypothesis that the Dalradian unconformably overlies the Annagh Gneiss Complex in north Mayo, whereas the detrital zircon data imply more distal Laurentian sources. Dalradian deposition is thereby tied to the margins of Laurentia. </p

Induction of mild systemic hypothermia with endovascular cooling during primary percutaneous coronary intervention for acute myocardial infarction

AbstractObjectivesThe purpose of this study was to evaluate the safety and feasibility of endovascular cooling during primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI).BackgroundIn experimental models of AMI, mild systemic hypothermia has been shown to reduce metabolic demand and limit infarct size.MethodsIn a multi-center study, 42 patients with AMI (<6 h from symptom onset) were randomized to primary PCI with or without endovascular cooling (target core temperature 33°C). Cooling was maintained for 3 h after reperfusion. Skin warming, oral buspirone, and intravenous meperidine were used to reduce the shivering threshold. The primary end point was major adverse cardiac events at 30 days. Infarct size at 30 days was measured using 99mTc-sestamibi SPECT imaging.ResultsEndovascular cooling was performed successfully in 20 patients (95%). All achieved a core temperature below 34°C (mean target temperature 33.2 ± 0.9°C). The mean temperature at reperfusion was 34.7 ± 0.9°C. Cooling was well tolerated, with no hemodynamic instability or increase in arrhythmia. Nine patients experienced mild episodic shivering. Major adverse cardiac events occurred in 0% vs. 10% (p = NS) of treated versus control patients. The median infarct size was non-significantly smaller in patients who received cooling compared with the control group (2% vs. 8% of the left ventricle, p = 0.80).ConclusionsEndovascular cooling can be performed safely as an adjunct to primary PCI for AMI. Further clinical trials are required to determine whether induction of mild systemic hypothermia with endovascular cooling will limit infarct size in patients undergoing reperfusion therapy