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Biomedical subjects

M A Kutcher

Publications and source records attributed to M A Kutcher.

12 recordsLinked to original sources
PubMed1997

Transluminal extraction catheter atherectomy followed by immediate stenting in treatment of saphenous vein grafts.

OBJECTIVES: The purpose of this study was to evaluate the effectiveness of transluminal extraction catheter (TEC) atherectomy followed by immediate Palmaz-Schatz coronary stenting of coronary bypass vein grafts. BACKGROUND: Degeneration of saphenous vein coronary bypass grafts has become a common problem. Repeat bypass surgery is associated with greater risk and a poorer outcome than the initial operation. Moreover, percutaneous interventional procedures in vein grafts have been associated with high procedural complication rates, including distal embolization, and high restenosis rates. TEC atherectomy may reduce distal embolization, and stenting may reduce restenosis rates. METHODS: We evaluated the procedural, hospital and clinical outcomes of TEC atherectomy followed by immediate Palmaz-Schatz coronary stenting of 53 vein grafts in 49 consecutive patients. The strategy was to limit instrumentation to extraction debulking and to stabilizing the site with stent deployment before using balloon dilation for optimal gain in lumen diameter. RESULTS: Results are shown as mean value (95% confidence interval [CI]). The mean graft age was 9.2 years (95% CI 7.9 to 10.5), and 1.0 (95% CI 1 to 1) TEC cutter (2.2 mm [95% CI 2.1 to 2.3]) and 1.7 (95% CI 1.4 to 2.0) Palmaz-Schatz coronary stents/ vein graft were used. The procedural success rate was 98%, with a minimal lumen diameter at baseline of 1.3 mm (95% CI 1.1 to 1.5), increasing to 3.9 mm (95% CI 3.6 to 4.2) (p < 0.05) after the TEC-stent procedure. Procedural complications occurred infrequently: graft perforation in 1 (2%) of 53 patients and distal embolization in 1 (2%) of 53 (same patient). In-hospital complications included non-Q wave myocardial infarction in two patients and death after a successful procedure in three (6%) (n = 1 each: massive bleeding from the catheter site; sepsis; and acute myocardial infarction with asystole in the distribution of the stented vessel). The event-free survival rate to hospital discharge was 90%. Clinical follow-up (13 months [95% CI 11 to 15]) was available for all patients. There were five (11%) revascularization procedures (three bypass grafts and two percutaneous transluminal coronary interventions), four (9%) nonfatal myocardial infarctions and five (11%) deaths, for a cumulative rate of 28% for any adverse outcome occurring in 13 of 46 patients. CONCLUSIONS: TEC atherectomy followed by immediate Palmaz-Schatz coronary stenting of stenoses in old (> 9 years) saphenous vein grafts can be successfully performed, with a low incidence of procedural and hospital complications. Clinical restenosis rates are low and less than those previously reported; however, late morbid cardiac events are still frequent in this high risk group of patients. These observational findings suggest that this technique may improve percutaneous management of vein graft disease, but optimal long-term management strategies remain to be determined.

Aged↗
PubMed1996

Venous activated clotting time after intra-arterial heparin: effect of site of administration and timing of sampling.

It is not known how the site of arterial administration of heparin and the timing of the activated clotting time (ACT) measurement affect the ACT during coronary interventions. We measured serial femoral venous ACTs after heparin was administered either via the angioplasty guiding catheter into the central aorta or peripherally via a sheath into the femoral artery. When heparin was administered into the central aorta, the ACT rose gradually and by 60 sec plateaued without further increase. When heparin was given into the femoral artery, the ACT displayed a marked "overshoot" early (20-270 sec after heparin) and did not plateau until sometime between 270 and 800 sec after heparin administration. We conclude that the site of administration and timing of venous sampling markedly affect the measured ACT during coronary interventions. Operators should be aware of these effects when assessing the accuracy of the ACT during coronary interventions.

Angioplasty, Balloon, Coronary↗
PubMed1995

The effects of intracoronary adenosine on preconditioning during coronary angioplasty.

There is evidence that the first balloon inflation during coronary angioplasty provides a preconditioning stimulus leading to decreased ischemia during subsequent balloon inflations. Endogenous adenosine release may play a role in ischemic preconditioning. Therefore, intracoronary adenosine administration prior to the first balloon inflation during percutaneous transluminal coronary angioplasty (PTCA) might modify the preconditioning response to the first balloon inflation. Forty-one patients underwent double-blind randomization to treatment with 100 mcg of intracoronary adenosine or placebo prior to coronary angioplasty. Twenty patients (11 adenosine, 9 placebo) had complete resolution of ischemia between inflations allowing comparison between the first and second inflation. An angioplasty guidewire was used to obtain an intracoronary electrocardiogram. The mean reduction in ST elevation during the second inflation compared with the first was 4.8 mm in the placebo group and -0.8 in the adenosine group (p < 0.05 placebo vs. adenosine). Seven of 9 placebo patients had a decrease in ischemia during the second inflation compared with the first, while only 2 of 11 adenosine patients showed a reduction. It was concluded that (1) the first inflation during PTCA is a preconditioning stimulus leading to a decrease in ischemia during later inflations, and (2) intracoronary adenosine administration prior to PTCA modifies the preconditioning effect of the first inflation. These data suggest that adenosine plays a role in ischemic preconditioning in humans.

Adenosine↗
PubMed1994

Qualitative and quantitative contrasts in the mechanisms of lumen enlargement by coronary balloon angioplasty and directional coronary atherectomy.

OBJECTIVES: This study was designed to define and contrast the mechanisms of lumen enlargement from coronary balloon angioplasty and directional coronary atherectomy using intracoronary ultrasound imaging in vivo. BACKGROUND: The mechanisms of lumen enlargement produced by percutaneous transluminal coronary balloon angioplasty and directional coronary atherectomy are not known because the coronary artery wall has not previously been studied both before and after dilation. METHODS: We used intracoronary ultrasound to quantitate coronary lumen, vessel and plaque area both before and immediately after successful coronary angioplasty (n = 30) and directional coronary atherectomy (n = 25) at the site of most severe stenosis. RESULTS: Angioplasty increased lumen area by 2.80 +/- 0.25 mm2 (mean +/- SE, p < 0.0001). Eighty-one percent of this lumen gain resulted from an increase in vessel area and the remaining 19% from a reduction in plaque area. Lumen gain of individual lesions was separated into three groups: 67% had an increase in vessel area (vessel expansion), 13% had a decrease in plaque area and 20% had a combination of both. In contrast, vessel expansion contributed only 22% of the lumen gain with directional coronary atherectomy, with the majority (78%) of increase in lumen size coming from a reduction in plaque area. Directional coronary atherectomy increased lumen area from 2.36 +/- 0.05 to 7.00 +/- 0.28 mm2 (p < 0.0001). Plaque reduction was the sole mechanism in 60% of lesions, vessel expansion was the sole mechanism in 12% and a combination of both mechanisms occurred in 28%. Lumen enlargement of eccentric lesions treated with directional coronary atherectomy was more commonly associated with plaque reduction (p < 0.02), whereas eccentricity did not affect the mechanism of lumen enlargement with coronary angioplasty. CONCLUSIONS: This is the first study to systematically examine the coronary artery wall in vivo at the site of a severe stenosis both before and after catheter-based interventions in humans. Lumen enlargement from coronary angioplasty occurs predominantly from vessel expansion or stretching, although a reduction in plaque area contributes to the lumen gain in many patients and is the sole mechanism in a few. Lumen gain from directional coronary atherectomy is predominantly from reduction in plaque area (probably owing to tissue removal), although vessel stretching (balloon effect) occurs and is the sole mechanism in a small minority of vessels. Plaque reduction is more common in directional coronary atherectomy of eccentric lesions.

Adult↗
PubMed1989

Acute Epstein-Barr virus myocarditis simulating myocardial infarction with cardiogenic shock.

We have reported the case of a 38-year-old white woman with substernal chest pain, hypotension, and ECG changes suggesting acute anterior myocardial infarction. Cardiac catheterization revealed no coronary artery pathology, but severe global hypokinesia was noted on left ventriculogram and endomyocardial biopsy revealed myocytic degeneration and mononuclear cell infiltration consistent with acute viral myocarditis. Viral serologies confirmed a recent Epstein-Barr virus infection.

Acute Disease↗
PubMed1988

A microcomputer based automated, quantitative coronary angiographic analysis system.

Rapid and accurate assessment of coronary artery stenotic severity is important in therapy and understanding of coronary artery disease. Since automated systems minimize prejudice and variations in analysis, we developed an automated, quantitative coronary analysis system utilizing an IBM PC-XT computer. Film images (35 mm) were cine-to-video converted and subsequently digitized by an IBM PC-XT computer. Given an approximate center line, the computer automatically detected edges, corrected for X-ray magnification, and calculated arterial dimensions. On objects of known dimensional sizes, the correlation coefficient between actual and calculated dimensions was 0.996 (p less than 0.01) with a standard error of estimate of 0.07 mm and +/- 3.0% reproducibility. For objects less than 1 mm in diameter, the standard error of estimate was 0.05 mm with +/- 4.1% reproducibility. However, with minimal contrast material (25%), the standard error of estimate increased to 0.20 mm with +/- 7.2% reproducibility. The results indicate that automated, quantitative coronary angiography can be achieved using an inexpensive IBM PC-XT based system, provided that the vessels are adequately opacified.

Adult↗
PubMed1988

Can coronary angiography predict the site of a subsequent myocardial infarction in patients with mild-to-moderate coronary artery disease?

To help determine if coronary angiography can predict the site of a future coronary occlusion that will produce a myocardial infarction, the coronary angiograms of 42 consecutive patients who had undergone coronary angiography both before and up to a month after suffering an acute myocardial infarction were evaluated. Twenty-nine patients had a newly occluded coronary artery. Twenty-five of these 29 patients had at least one artery with a greater than 50% stenosis on the initial angiogram. However, in 19 of 29 (66%) patients, the artery that subsequently occluded had less than a 50% stenosis on the first angiogram, and in 28 of 29 (97%), the stenosis was less than 70%. In every patient, at least some irregularity of the coronary wall was present on the first angiogram at the site of the subsequent coronary obstruction. In only 10 of the 29 (34%) did the infarction occur due to occlusion of the artery that previously contained the most severe stenosis. Furthermore, no correlation existed between the severity of the initial coronary stenosis and the time from the first catheterization until the infarction (r2 = 0.0005, p = NS). These data suggest that assessment of the angiographic severity of coronary stenosis may be inadequate to accurately predict the time or location of a subsequent coronary occlusion that will produce a myocardial infarction.

Adult↗
PubMed1986

Ventricular coupling in constrictive pericarditis.

Because of the close anatomic association, the volume or pressure in one ventricle can directly influence the volume and pressure in the other ventricle. Disease states that reduce pericardial compliance should accentuate this coupling between the ventricles. We examined this hypothesis in six dogs. Constrictive pericarditis was induced by injecting an irritant mixture into the pericardial cavity. Three to 4 weeks after this injection, the hearts were removed and placed in cool cardioplegic solution. Balloons were inserted into each ventricle and the pressure and volume changes caused by increasing the contralateral ventricular volume were measured. Compared with that in a control group of four dogs, the coupling between the ventricles was significantly augmented in the group with constrictive pericarditis. All the measured changes in ventricular pressure or volume caused by increasing contralateral ventricular pressure or volume were significantly greater (p less than .05) in the group with constrictive pericarditis. The results of these experiments show increased coupling between the ventricles with constrictive pericarditis, which helps to explain some of the signs and symptoms of constrictive pericarditis.

Animals↗
PubMed1983

Constrictive pericarditis following cardiac surgery; a complication that does exist.

Constrictive pericarditis as a complication of cardiac surgery does exist. Although the problem is somewhat uncommon, it should be suspected in patients following cardiac surgery who present with deteriorating cardiac function. The clinical spectrum of the disease is wide and may present as true rigid shell constriction or a more subtle form of elastic sero-effusive construction. It is imperative for the physician to consider this entity in the differential of complications following cardiac surgery.

Adult↗
PubMed1982

Constrictive pericarditis as a complication of cardiac surgery: recognition of an entity.

Among 5,207 adult patients who underwent cardiac surgery, postoperative constrictive pericarditis was recognized in 11 patients (0.2% incidence rate). Seven patients had coronary arterial bypass grafting and 4 had valve replacement; the pericardium was left open in all cases. The average interval between surgery and presentation of pericardial constriction was 82 days (range 14 to 186). M mode echocardiography revealed epicardial and pericardial thickening in 7 cases and variable degrees of posterior pericardial effusion in 5 cases. Cardiac catheterization demonstrated uniformity of diastolic pressures with a characteristic early diastolic dip and late plateau pattern. Two patients responded to medical therapy for chronic pericarditis. One patient had a limited parietal pericardiectomy followed by recurrent constrictive pericarditis that eventually stabilized with medical therapy. The other 8 patients required radical pericardiectomy. The pathophysiology of constriction after surgery is unclear. Its clinical expression involves a wide spectrum of presentation and therapeutic response. Constrictive pericarditis may be a complication of cardiac surgery in spite of an open pericardium and should be considered in postoperative patients who present with deteriorating cardiac function.

Adrenal Cortex Hormones↗