Joshua Wynne

Percutaneous coronary laser balloon angioplasty: Initial results of a multicenter experience

A multicenter clinical trial was initiated to test the potential safety and short-term efficacy of a percutaneous coronary application of laser balloon angioplasty, which has been shown experimentally to alleviate the common causes (dissection, recoil, thrombus) of suboptimal luminal results of conventional balloon angioplasty. Fifty-five patients, the majority (62%) of whom had relatively high risk lesions, were treated in 10 centers with a laser balloon that was identical in size (3 x 20 mm) to a balloon used for conventional balloon angioplasty performed on the same lesion immediately before laser balloon angioplasty. One or more neodymium:yttrium aluminum garnet (Nd:YAG) (1,060 nm) laser doses of 250 to 450 J were each delivered over a 20 s duration per exposure. Immediately and 1 day after laser balloon angioplasty no significant adverse effects on the arterial lumen were noted in any patient. By computerized image analysis of cineangiograms initial conventional balloon angioplasty failed to achieve a minimal luminal diameter greater than 1.5 mm in 14 patients (25%), including 3 patients with acute closure. However, after subsequent laser balloon angioplasty, minimal luminal diameter exceeded this value in all patients including this subgroup. Overall, minimal luminal diameter increased from 1.74 +/- 0.46 mm after conventional balloon angioplasty to 2.32 +/- 0.31 mm after laser balloon angioplasty (p less than 0.001) with no change found on 1 day and 1 month follow-up angiograms. Thus, laser balloon angioplasty is a safe, effective procedure for improving luminal dimensions after conventional balloon angioplasty.

5-Fluorouracil Cardiotoxicity: Left Ventricular Dysfunction and Effect of Coronary Vasodilators

ABSTRACT: Seven patients developed clinical features simulating myocardial ischemia less than 72 hours after 12 of 13 separate invenous 5-flourouracil administrations; 9 episodes were associated with chest pain, 3 with hypotension, 3 with ventricular tachycardia and 1 with cardiogenic shock. Left ventricular dysfunction was demonstrated by echocardiography in 5 separate episodes, 2 with interval improvement upon repeat echocardiograms. Pretreatment with nitrates and/or calcium channel blockers failed to prevent recurrence of cardiotoxicity during 5 of 6 repeat 5-fluorouracil administrations. Therapy with 5-fluorouracil is associated with cardiotoxicity simulating myocardial ischemia with left ventricular dysfunction. Pretreatment with coronary vasodilators may not prevent this phenomenon.

The clinical syndrome of 5-fluorouracil cardiotoxicity

Summary5-fluorouracil (FUra) is one of the most frequently used drugs in cancer treatment, particularly in combination with other agents. Its activity when administered as an infusion rather than a bolus has led to a renewed and increased use. A cardiotoxicity that mimics ischemia has been associated with the administration of FUra in cancer patients. This cardiotoxicity may manifest itself as: (a) dysrythmias with and without cardiorespiratory symptoms (b) ECG changes with and without cardiorespiratory symptoms (c) cardiorespiratory symptoms with and without ECG changes (d) acute myocardial infarct; symptoms and ECG changes (e) ventricular dysfunction (f) cardiogenic shock and (g) sudden death. Several case studies which illustrate the cardiotoxic sequelae that may be associated with the use of this drug are discussed. The incidence, contributing factors, risk factors and mechanisms underlying this phenomenon are undetermined. No appropriate recommendations for monitoring patients or for predicting those patients that will develop such toxicity while receiving FUra can be made at present. Prospective studies to determine the true incidence, spectrum and mechanisms causing this syndrome are ongoing and required for its understanding and prevention.

Reassessment of the association between gastrointestinal arteriovenous malformations and aortic stenosis

PURPOSE AND PATIENTS AND METHODS The purported association between aortic stenosis and gastrointestinal arteriovenous malformations (AVMs) has not been rigorously evaluated. The diagnosis of aortic stenosis in most the prior studies has been based on clinical examination. We therefore utilized two-dimensional and Doppler echocardiography to document the presence or absence of aortic stenosis in 29 men with gastrointestinal AVMs documented by endoscopy. RESULTS Of the 29 patients studied, 22 (76 percent) had ejection systolic murmurs and 18 (62 percent) had echocardiographic evidence of aortic sclerosis. However, none of the patients had any evidence of aortic stenosis as assessed by Doppler echocardiography. CONCLUSION Although previous case reports and retrospective studies have suggested an association between gastrointestinal AVMs and aortic stenosis, our study does not support this association and suggests the need for a prospective trial.

Dose-related efficacy and bleeding complications of double-chain tissue plasminogen activator in acute myocardial infarction

Although the efficacy of recombinant tissue-type plasminogen activator (rt-PA) in acute myocardial infarction has been demonstrated, little formal dose-ranging information is available. This study examined the use of duteplase, the double-chain rt-PA subsequently used in the Third International Study of Infarct Survival, in a multicenter trial of 267 patients with evolving acute myocardial infarction assigned to receive 1 of 6 weight-adjusted doses. The primary end point was infarct vessel patency after 90 minutes of drug infusion. Patency was defined as Thrombolysis in Myocardial Infarction trial grade 2 or 3 perfusion, and was determined by an independent core laboratory masked to treatment assignment. Patency was present in 48% of patients receiving the lowest dose range and 78% of those receiving the highest, with an association between thrombolytic dose and patency (p = 0.009). The frequency of serious bleeding complications also correlated with the total dose of rt-PA infused (p = 0.003). Bleeding complications were primarily related to instrumentation; blood loss requiring transfusion or otherwise deemed clinically significant occurred in 12% of patients (central nervous system hemorrhage occurred in 1.1%). Thus, higher doses of rt-PA are associated both with increased efficacy and increased risk of serious bleeding complications. Weight-adjusted dosing may provide an optimal risk-benefit ratio for thrombolysis during acute myocardial infarction.

Use of balloon pull-through technique to assist in cardioSEAL device closure of patent foramen ovale

CardioSEAL device closure of patent foramen ovale (PFO) has been advocated for the treatment of patients with cryptogenic stroke. Using the standard delivery technique, partial deployment of the CardioSEAL device can occur, especially in patients with a thick septum secundum and/or long PFO tunnel. We hypothesized that using a left atrial‐to‐right atrial balloon pull‐through to make the septum primum incompetent would result in improved final device position regardless of septal thickness or tunnel length. Catheterization reports, cineangiograms, and transesophageal echocardiograms of 51 patients who underwent CardioSEAL device closure of PFO between March 2000 and August 2002 were retrospectively reviewed. Group 1 (n = 21) included patients with CardioSEAL placement using the standard technique and group 2 (n = 30) included patients with CardioSEAL placement using the balloon pull‐through technique. There were no differences between the groups in terms of age (43.6 vs. 45.3 years; P = NS), weight (83.3 vs. 89.9 kg; P = NS), septum secundum thickness (6.4 vs. 7.0 mm; P = NS), PFO tunnel length (15.5 vs. 13.1 mm; P = NS), or device size. In group 1, 4/21 (19%) had partial deployment of the CardioSEAL device, while in group 2, no partial CardioSEAL deployment (0/30) was observed. No complications were associated with the balloon pull‐through technique. We conclude that the left atrial‐to‐right atrial balloon pull‐through technique is safe and may allow for better final position of the CardioSEAL device during PFO closure. Catheter Cardiovasc Interv 2003;60:101–106.

Effect of milrinone on acute myocardial infarct size

Abstract Milrinone has been reported to possess positive inotropic activity in normal anesthetized and conscious dogs, in anesthetized dogs with drug-induced heart failure, 1 and in patients with severe congestive heart failure. 2 Previous studies have suggested that inotropic stimulation of the infarcting heart could extend the amount of necrosis. 3 Whether milrinone has such an effect is unknown. Thus, the aim of this report was to investigate the effect of milrinone on acute myocardial infarct size and hemodynamics in an anesthetized canine model of acute myocardial infarction.

Capital budgeting practices in hospitals

We interviewed chief financial officers from hospitals and healthcare systems in Michigan regarding selected capital budgeting practices that have not been previously considered in the literature. Results revealed a variety of approaches in the development and deployment of capital budgets. Most healthcare systems used a blend of board and department-initiated input into budget development, usually with interaction between the two. The majority of healthcare systems had flexibility in the deployment of their capital budgets over time. Standard methods of project evaluation were employed by healthcare CFOs, but few used the most sophisticated tools. A host of constraints, including certificate-of-need laws and internal, mission-based motivations uniquely affect capital budgeting of not-for-profit healthcare systems. Clearly, future research will be need to understand why organisations have selected capital budgeting practices and the extent to which selection and use of capital budgeting practices matters in the efficiency and viability of healthcare systems.

Pentoxifylline does not reduce infarct size in a canine model of acute myocardial infarction.

1 The effect of the haemorrheological agent pentoxifylline was investigated in a canine model of acute myocardial infarction, induced by occlusion of the left anterior descending coronary for 6 h. Thirty minutes post‐occlusion the dogs were randomized to receive either distilled water or pentoxifylline (0.3 mg kg−1 min−1 for 1 h followed by 0.15 mg kg−1 min−1 for 4.5 h) intravenously. 2 At 6 h post‐occlusion the in vivo area at risk was determined with monastral blue dye and the area of necrosis was determined with triphenyltetrazolium chloride. The area at risk was 16.5 ± 1.3% in the control group (n = 10) and 17.2 ± 1.8% in the pentoxifylline treated group (n = 10; NS). The area of necrosis was 12.3 ± 1.9% in the control group and 11.9 ± 2.2% in the pentoxifylline treated group (NS). The area of necrosis expressed as a percentage of the area at risk was 69.3 ± 7.7% in the control group and 63.6 ± 7.4% in the pentoxifylline treated group (NS). 3 Pentoxifylline had no significant effects on heart rate, systolic or diastolic blood pressure. Regional myocardial blood flow, measured by the radioactive microsphere technique, was not significantly different between the groups. 4 Thus, pentoxifylline does not reduce infarct size in this model of acute myocardial infarction and does not enhance coronary collateral blood flow.