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Biomedical subjects

A D Cannon

Publications and source records attributed to A D Cannon.

9 recordsLinked to original sources
PubMed1995

Length of hospital stay and complications after percutaneous transluminal coronary angioplasty. Clinical and procedural predictors. Heparin Registry Investigators.

BACKGROUND: Although several studies have established that the complications of percutaneous transluminal coronary angioplasty (PTCA) are related to clinical and angiographic variables such as advanced age and lesion complexity, it is uncertain whether the use of hospital resources after PTCA also depends on the same baseline variables. The purpose of this study was to identify the factors responsible for prolonged hospital stay after PTCA. METHODS AND RESULTS: The study cohort included 591 consecutive patients undergoing conventional balloon angioplasty at nine medical centers in North America. Major or minor complications occurred in 91 patients (15.4%) and were observed to be related to several baseline characteristics, including unstable angina, multivessel coronary artery disease, patient age, and lesion complexity. Compared with a median length of hospital stay of 2.0 days after PTCA (25th, 75th percentiles: 2.0, 4.0) for the entire cohort of patients, the length of stay was increased in patients with unstable angina (3.0 days [2.0, 5.0]; P = .002), multivessel coronary artery disease (3.0 [2.0, 5.5]; P = .001), age > 65 years (3.0 [2.0, 5.5]; P = .02), complex lesions (3.0 [2.0, 6.0]; P = .001), and filling defects (6.0 [2.0, 11.0]; P < .001). The length of stay was more strikingly increased, however, in patients who experienced major or minor PTCA complications, such as emergency bypass surgery (9.0 days [8.0, 18.0]; P < .001), Q-wave or non-Q-wave myocardial infarction (8.0 [6.0, 15.5]; P < .001), transfusion unrelated to bypass surgery (8.0 [4.0, 12.0]; P < .001), or abrupt vessel closure (6.0 [3.0, 10.5]; P < .001). On stepwise multiple linear regression, PTCA complications appeared to be the strongest predictors of length of hospital stay (all P < .001) and overwhelmed the weaker relation between length of stay and several individual baseline variables. Inclusion of a composite clinical risk score (reflecting the presence of unstable angina, multivessel disease, advanced age, complex lesions, or filling defects) in the regression model confirmed that patients with several high-risk baseline variables had a significant increase in length of stay after PTCA (P = .003), but PTCA complications remained the strongest predictors of length of stay. CONCLUSIONS: Although PTCA complications were correlated with baseline variables such as unstable angina, multivessel disease, advanced age, complex lesions, and filling defects, excess length of stay after PTCA was most strongly influenced by the development of minor and major PTCA complications. Because patients with several baseline risk factors experienced significantly prolonged hospitalizations, improved selection of patients may contribute to reductions in length of stay after PTCA. A greater reduction in resource use after PTCA, however, would be expected from developing new treatments to decrease PTCA complications rather than limiting the access of patients with unstable angina, advanced age, or complex lesions to PTCA.

Aged↗
PubMed1994

Acute angiographic and clinical results of long balloon percutaneous transluminal coronary angioplasty and adjuvant stenting for long narrowings.

Historically, long coronary artery stenoses undergoing percutaneous transluminal coronary angioplasty (PTCA) are reported to have reduced procedural and clinical success in comparison with shorter lesions. The efficacy of long balloons (30 or 40 mm) in long lesions was evaluated. Eighty-two patients had 84 PTCA procedures with a primary long balloon. In all, 86 lesions were available for analysis. Data were collected prospectively on standard PTCA procedure forms. Coronary angiograms were reviewed and measured with digital calipers. Hospital charts were examined for complications. PTCA was performed in the left anterior descending artery in 44 cases (51%), the right coronary artery in 29 (34%) and the circumflex artery in 13 (15%). With the use of a modified classification system, 47 lesions (55%) were class C, 24 (28%) were class B2 and 15 (17%) were class B1. Mean lesion length was 22 +/- 11 mm (range 10 to 72), and 38 lesions (44%) were > or = 20 mm. Twelve patients received an intracoronary stent. The long balloon alone produced angiographic success (< 50% residual stenosis) in 77 lesions (90%). Angiographic success was achieved ultimately in all stenoses, using a stent in 7 patients and a short balloon in 2. There were 2 deaths (2%) and 1 Q-wave myocardial infarction (1%). One patient needed coronary artery bypass surgery. Clinical success without death, Q-wave infarction or bypass surgery was achieved in 83 of 86 procedures (97%). In conclusion, the use of long PTCA balloons with adjuvant stenting produced excellent results in these long stenoses. Lesion length was not a precursor of poor angiographic or clinical outcome.

Adult↗
PubMed1994

Balloon angioplasty for treatment of in-stent restenosis: feasibility, safety, and efficacy.

Sixty patients with 1 or 2 stainless steel intracoronary stents (Cook, Inc.) underwent balloon angioplasty for in-stent restenosis 1.5-13.5 months after stenting. Seventy-five in-stent redilatation procedures were performed. Seventy-three restenotic lesions (97%) were successfully recrossed and dilated, reducing the mean pre-angioplasty intrastent diameter stenosis from 77 +/- 12% to 20 +/- 11% residual. Although one angioplasty (1.3%) was complicated by non-Q-wave infarction, no angioplasty-related death, acute closure, need for additional stenting, emergent coronary bypass surgery, side branch occlusion, or vascular sequelae occurred. Post-procedure heparin was not used in 83% of successful cases. Most patients were discharged the day following redilatation (mean in-hospital stay 1.7 +/- 1.3 days). At 5.4 +/- 3.4 months following in-stent angioplasty, 84% of patients were in Canadian Cardiovascular Society class 0 or I. In conclusion, balloon dilatation in this stent for restenosis appears simple and efficacious in the short term, and may entail less risk than dilatation of unprotected coronary vessels.

Adult↗
PubMed1992

Nonsurgical closure of femoral pseudoaneurysms complicating cardiac catheterization and percutaneous transluminal coronary angioplasty.

OBJECTIVES: This study was performed to describe the initial experience and follow-up of ultrasound-guided compression of pseudoaneurysms in patients receiving systemic anticoagulant or antiplatelet therapy, or both, after recent cardiac catheterization or percutaneous transluminal coronary angioplasty. BACKGROUND: Femoral artery pseudoaneurysm formation after an interventional procedure is becoming more common as larger caliber catheters and prolonged anticoagulant and antiplatelet therapy are being used. Traditional treatment of this complication has been surgical repair. This study describes a new method of closing femoral pseudoaneurysms by using external compression guided by Doppler color flow imaging. METHODS: Fifteen patients, 3 undergoing cardiac catheterization and 12 undergoing coronary angioplasty, developed an expansile groin mass at the vascular access site diagnosed as a femoral artery pseudoaneurysm by Doppler ultrasound. Seven of the patients had undergone coronary stenting and were receiving postprocedural anticoagulant therapy. These patients underwent progressive graded mechanical (C-clamp) external compression guided by ultrasound. The mechanical compression was titrated to obliterate the vascular tracts to these aneurysms and maintain adequate flow in the femoral artery. RESULTS: After an average compression time of 30 min (range 10 to 120), these tracts remained closed. Follow-up ultrasound examination at 24 h or later confirmed continued closure in all. CONCLUSIONS: This study suggests that nonsurgical closure of femoral pseudoaneurysms is feasible. This technique may be valuable in managing vascular access-related complications after diagnostic and interventional procedures, even in patients requiring prolonged anticoagulant therapy.

Adult↗
PubMed1992

Intracoronary stenting for acute and threatened closure complicating percutaneous transluminal coronary angioplasty.

BACKGROUND. Acute closure remains a significant limitation of percutaneous transluminal coronary angioplasty (PTCA) and underlies the majority of ischemic complications. This study details the clinical and angiographic characteristics of a series of patients receiving an intracoronary stent device to manage acute and threatened closure and presents the early clinical results. METHODS AND RESULTS. From October 1989 through June 1991, 115 patients undergoing PTCA received intracoronary stents to treat acute or threatened closure in 119 vessels. Sixty-three percent had multivessel coronary disease, 33 (29%) had undergone prior coronary artery bypass grafting (CABG), and 52 (45%) had had previous PTCA. Using the American College of Cardiology/American Heart Association (ACC/AHA) classification, 15% of lesions were class A, 55% were class B, and 30% were class C. Eight patients were referred with severe coronary dissection and unstable angina after PTCA at other institutions. Acute closure was defined as occlusion of the vessel with TIMI (Thrombolysis in Myocardial Infarction) 0 or 1 flow immediately before stent placement. Threatened closure required two or more of the following criteria: 1) a residual stenosis greater than 50%, 2) TIMI grade 2 flow, 3) angiographic dissection comprising extraluminal dye extravasation and/or a length of greater than 15 mm, 4) evidence of clinical ischemia (either typical angina or ECG changes). Twelve vessels (10%) met the criteria for acute closure, and 87 vessels (73%) satisfied the criteria for threatened closure. Twenty vessels (17%) failed to meet two criteria. Stenting produced optimal angiographic results in 111 vessels (93%), with mean diameter stenosis (+/- 1 SD) reduced from 83 +/- 12% before to 18 +/- 29% after stenting. Overall, in-hospital mortality was 1.7% and CABG was required in 4.2%; Q wave myocardial infarction (MI) occurred in 7% and non-Q wave MI in 9%. Stent thrombosis occurred in nine patients (7.6%). For the 108 patients who presented to the catheterization laboratory without evolving MI, Q wave MI occurred in 4% and non-Q wave MI occurred in 7%. Angiographic follow-up has been performed in 81 eligible patients (76%), and 34 patients (41%) had a lesion of greater than or equal to 50%. CONCLUSIONS. This stent may be a useful adjunct to balloon dilatation in acute or threatened closure. Randomized studies comparing this stent with alternative technologies are required.

Angioplasty, Balloon, Coronary↗