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Biomedical subjects

H G Kemp

Publications and source records attributed to H G Kemp.

At least 19 recordsLinked to original sources
PubMed1992

Percutaneous transluminal coronary angioplasty in New York State. Risk factors and outcomes.

OBJECTIVE: To identify significant independent risk factors for major percutaneous transluminal coronary angioplasty outcomes. DESIGN: Retrospective analysis using univariate and logistic regression analysis to identify significant independent risk factors for adverse outcomes. SETTING: All 31 hospitals performing percutaneous transluminal coronary angioplasty in New York State in 1991. PATIENTS: All 5827 patients undergoing percutaneous transluminal coronary angioplasty between January 1, 1991, and June 30, 1991, in New York State. MAIN OUTCOME MEASURES: In-hospital mortality, major complication(s) (in-hospital mortality, myocardial infarction, and/or emergency coronary artery bypass graft), and absence of angiographic success (stenosis reduction of less than 20% on any attempted lesion or residual stenosis of at least 50% on any attempted lesion). MAIN RESULTS: Before discharge from the hospital, a total of 37 patients (0.63%) died; 67 patients (1.1%) suffered a myocardial infarction, with a mortality rate of 4.5%; and 97 patients (1.7%) underwent emergency coronary artery bypass graft surgery, with a mortality rate of 2.1% (no deaths in 85 patients who were hemodynamically stable and two deaths among 12 patients who were hemodynamically unstable). A total of 187 patients (3.2%) experienced a major complication. Angiographic success was achieved for 88% of all patients. Multivariate analysis found four independent preprocedural variables related to death: female gender, hemodynamic instability, shock, and ejection fraction. CONCLUSIONS: Percutaneous transluminal coronary angioplasty outcomes in New York compare favorably with other recent results reported in the literature. Several preprocedural variables markedly increase the incidence of adverse events.

Aged↗
PubMed1989

A complication of prolonged urokinase infusion into a chronically occluded aortocoronary saphenous vein graft.

Recanalization of a chronically occluded aortocoronary saphenous vein graft was performed, using a prolonged intracoronary infusion of urokinase followed by percutaneous transluminal coronary angioplasty (PTCA). Despite an angiographically successful result, the patient developed acute myocardial infarction, presumably secondary to distal migration of partially lysed thrombus. One week after successful angioplasty, the graft was once again proximally occluded.

Coronary Artery Bypass↗
PubMed1988

Unusually long inflation times during percutaneous transluminal coronary angioplasty.

Unusually prolonged balloon inflations (PBI) during percutaneous transluminal coronary angioplasty (PTCA) have been utilized in 26 consecutive patients to establish adequate coronary perfusion after shorter inflation times resulted in severe residual stenosis (N = 15), early arterial closure (N = 5), or extensive dissection (N = 6). Inflations lasted 1.5 to 15 min and 23/27 stenoses were successfully dilated. The average reduction in stenosis was 67% (90%-33%). Chest pain occurred in 34% vs. 7% (P less than 0.01), and ST changes occurred during 66% vs. 57% (NS) of PBI vs. short inflations. Four patients required coronary artery bypass surgery in spite of PBI, but none suffered an infarction. Electrocardiograms were unchanged in 22 patients and showed nonspecific ST-T wave changes in four. Cardiac enzymes obtained in nine patients failed to reveal a significant increase in serum concentration. We conclude that PBI is well tolerated and can successfully dilate lesions not responding to short inflations.

Adult↗
PubMed1988

Reoperation for coronary artery disease. 10 years of clinical follow-up.

From a 15-year follow-up study of 743 patients who underwent initial operation for coronary artery disease, 64 patients required reoperation for recurrence of angina and were followed-up for 15 years or less (mean, 6.2 years). Patients undergoing reoperation tended to be older but not significantly so (50.9 +/- 8.3 years vs. 57.5 +/- 9.7 years), had more left main coronary artery disease (p less than 0.001), and had more triple-vessel disease (p less than 0.001) than those undergoing the initial operation. There were no significant differences in sex, prior myocardial infarctions, or prevalence of abnormal ventriculograms between the two groups. The cumulative survival rate during a 10-year follow-up period after reoperation did not differ from the rate after the initial operations. There was less relief of angina in the first year after reoperation than after initial operation, but thereafter, the annual increases in recurrence of angina were similar. Although there were more myocardial infarctions after reoperation in the first 6 postoperative years, the cumulative incidence after 10 years did not differ between the two groups. We conclude that reoperation yields a similar survival benefit but produces less early relief of angina than initial operation.

Angina Pectoris↗
PubMed1987

Left main coronary artery stenosis following mediastinal irradiation.

The association of mediastinal radiation therapy and coronary artery disease has been documented over the past three decades. This report describes a case of left main coronary artery stenosis eight years after radiation therapy in a 27-year-old woman. The patient was a young woman with no risk factors for coronary artery disease who had development of new-onset angina at rest. At coronary arteriography, the patient was found to have a tight ostial left main stenosis. The association of mediastinal radiation therapy with fixed and vasospastic coronary artery disease is reviewed. With many patients treated by radiation therapy now surviving their thoracic malignancies, an enlarging young population may be susceptible to the early development of ischemic heart disease.

Adult↗
PubMed1987

Recurrent myocardial infarction associated with cocaine abuse in a young man with normal coronary arteries: evidence for coronary artery spasm culminating in thrombosis.

Myocardial infarction is increasingly recognized as a complication of cocaine abuse. A significant number of persons suffering from myocardial infarction associated with cocaine abuse do not have significant coronary atherosclerosis, and the mechanism for infarction in these patients has remained obscure. This report describes a young man with angiographically normal coronary arteries in whom cocaine abuse produced coronary artery spasm leading to coronary thrombosis and infarction.

Adult↗
PubMed1986

Seven year survival of patients with normal or near normal coronary arteriograms: a CASS registry study.

The effect on 7 year survival of having a normal or near normal coronary arteriogram was examined using data from the CASS registry of 21,487 consecutive coronary arteriograms taken in 15 clinical sites. Of these, 4,051 arteriograms were normal or near normal, and the patients had normal left ventricular function as judged by absence of a history of congestive heart failure, no reported segmental wall motion abnormality and an ejection fraction of at least 50%; 3,136 arteriograms were entirely normal and the remaining 915 revealed mild disease with less than 50% stenosis in one or more segments. The 7 year survival rate was 96% for the patients with a normal arteriogram and 92% for those whose study revealed mild disease (p less than 0.0001). Nine risk variables recorded at entry were analyzed for predictive value for survival: age, sex, height, weight, history of smoking, presence of absence of mild disease, electrocardiographic response to exercise, family history of coronary heart disease and a history of hypertension. Of these, age, smoking history, presence or absence of disease and a history of hypertension had predictive value.

Adult↗
PubMed1986

Bypass surgery with the internal mammary artery graft: 15 year follow-up.

We performed a 15 year follow-up of 748 patients undergoing bypass surgery, comparing 532 patients with one or two internal mammary artery grafts with or without additional saphenous vein grafts to 216 patients with saphenous vein grafts alone. During the 15 years of follow-up the 532 patients with at least one internal mammary artery bypass graft had better cumulative survival (p less than .01), less early recurrence of angina (p less than .01), fewer myocardial infarctions (p less than .02), fewer reoperations (p less than .001), and better cumulative event-free survival (p less than .01) than the 216 patients with vein grafts alone. Patients who developed angina postoperatively had a better cumulative survival (p less than .01) in the presence of an internal mammary graft than with vein grafts alone. The 38 patients with double internal mammary grafts had the best survival rates, with lowest recurrence of angina and rate of late myocardial infarction and no need for reoperation. We conclude the internal mammary graft gives better protection against the clinical manifestations of coronary artery disease than does the saphenous vein graft.

Adult↗
PubMed1985

Coronary arteriography: indications, techniques, and morbidity.

Coronary arteriography has evolved into a relatively safe and simple procedure, yielding important information about the patient with clinical manifestations of coronary heart disease. The clear trend is to employ arteriography earlier and more frequently in the evaluation. The major therapeutic modality dependent on arteriography at present is bypass surgery, but transluminal angioplasty is rapidly developing and will probably be applicable to an expanding portion of patients. Even newer is thrombolysis in acute myocardial infarction with its promise of limiting myocardial damage in that setting.

Angiography↗
PubMed1983

Increased risk of ventricular fibrillation associated with temporary pacemaker use during coronary arteriography.

Each injection of angiographic contrast dye during coronary arteriography represents a "natural experiment" in which the human ventricular fibrillation threshold is transiently reduced. Few factors, however, have been identified which favor the actual occurrence of ventricular fibrillation in this setting. Of 3906 consecutive patients undergoing selective coronary arteriography with sodium meglumine diatrizoate, 66 (1.7 percent) experienced dye-induced ventricular fibrillation, from which all were successfully defibrillated. Analysis of these cases revealed, unexpectedly, that patients in whom temporary right ventricular pacemakers were employed had an incidence of ventricular fibrillation nearly six times that found in the entire group undergoing arteriography (10 percent vs. 1.7 percent, respectively; P less than .001). Those individuals receiving pacemakers were distinguished from other studied patients only by a higher prevalence of conduction abnormalities. Although there is normally a low probability that mechanical stimulation by a pacing catheter can induce ventricular fibrillation, it is postulated that such an occurrence may be more likely after ventricular vulnerability has been increased by contrast dye.

Adult↗
PubMed1983

Aneurysmal coronary artery disease.

To examine the clinical and historical features and the natural history of aneurysmal coronary disease, we reviewed the registry data of the Coronary Artery Surgery Study (CASS). Nine hundred seventy-eight patients, representing 4.9% of the total registry population, were identified as having aneurysmal disease. No significant differences were noted between aneurysmal and nonaneurysmal coronary disease patients when features such as hypertension, diabetes, lipid abnormalities, family history, cigarette consumption, incidence of documented myocardial infarction, presence and severity of angina, and presence of peripheral vascular disease were examined. In addition, no difference in 5-year medical survival was noted between these two groups. These findings suggest that aneurysmal coronary disease does not represent a distinct clinical entity but is, rather, a variant of coronary atherosclerosis.

Aneurysm↗
PubMed1983

Left main coronary artery stenosis: angiographic determination.

Reliability of angiographic assessment of the left main coronary artery segment was evaluated by review of 106 coronary cineangiograms from the Coronary Artery Surgery Study. The films were interpreted by three groups of angiographers: those at a clinical site, those at a quality control site, and those on a study census panel. Among the readings of these three groups, there was 41% to 59% agreement on the severity of the lesion, with 80% agreement on whether the lesion was greater or less than 50%. The severity of lesion, its location, or presence of ectasia or calcium did not affect the discrepancy rate, whereas segments that were unusually short, diffusely diseased, or obscured by overlapping vessels were especially difficult to interpret.

Arterial Occlusive Diseases↗
PubMed1982

Interobserver variability in interpreting contrast left ventriculograms (CASS).

Randomly selected left ventricular cineangiograms performed by 14 medical centers (clinical sites) participating in a large multicenter study of medical and surgical treatment of coronary artery disease (CASS) were systematically recalled and reread by one of four designated quality control centers. The end diastolic volume (EDV), end systolic volume (ESV), and ejection fraction (EF) calculated by the quality control center were compared with those calculated by the clinical site, and correlation coefficients of 0.71, 0.84, and 0.79, respectively, were obtained. Regional left ventricular (LV) wall motion abnormalities were assessed by dividing the LV wall as viewed in the right anterior oblique (RAO) and left anterior oblique (LAO) views into five segments each and grading the motion of each segment according to six categories of increasing abnormalities from normal to aneurysm. When discrepancies based on "nearest neighbor" differences in naming adjacent segments were eliminated and only marked differences of more than one degree of severity of wall motion abnormality were considered, interobserver differences were 7% and 10% for RAO and LAO segments, respectively. Agreement was less frequent in designating a segment "aneurysmal." When each LV segment was assigned a numerical score based on increasing severity of wall motion abnormality and a total LV score for each ventriculogram computed, the quality control and clinical site readings were in good agreement with a correlation coefficient of 0.83.

Cardiac Volume↗
PubMed1979

Asynchronous ventricular relaxation: an angiographic temporal analysis of asynchronous left ventricular relaxation in man.

Segmental "early relaxation" is a common angiographic finding. An attempt was made to elucidate the temporal characteristics of this event. Twenty subjects with and 20 without segmental early relaxation were studied. The left ventricular diastolic relaxation time was precisely determined angiographically, and the findings were as follows: 0.12 +/- 0.04 second (mean +/- standard deviation) in the normal patients, 0.14 +/- 0.03 second in the patients with coronary artery disease but no segmental early relaxation and 0.20 +/- 0.04 second in the patients with segmental early relaxation. These findings indicate that early relaxation is associated with a significantly prolonged ventricular relaxation time. The use of the term asynchronous ventricular relaxation is proposed to denote the disturbed diastolic properties of the ventricle with "early relaxation."

Angiocardiography↗
PubMed1979

Complications of coronary arteriography from the Collaborative Study of Coronary Artery Surgery (CASS).

Data were collected prospectively on 7553 consecutive patients undergoing coronary arteriography. The studies were performed at 13 clinics of the Collaborative Study of Coronary Artery Surgery (CASS) using brachial and femoral techniques. There were eight deaths 0--24 hours and seven deaths 24--48 hours after arteriography (2/1000). There were 15 non-fatal myocardial infarctions (MIs) 0--24 hours and four MIs 24--48 hours after arteriography (2.5/1000). Of 657 cases with left main stenosis greater than or equal to 50%, five died and three had MI. Left main disease increased risk of death by 6.8 times (p less than 0.001). Other factors increasing risk were unstable angina, congestive heart failure, multiple premature ventricular contractions, and hypertension. Of the 1187 patients studied from the brachial artery, six died (0.51%) and five had MIs (0.42%). In 6328 patients studied from the femoral artery, nine died (0.14%) and 14 had MIs (0.22%). The brachial artery technique increased the risk of death 3.6 times compared with the femoral approach (p less than 0.05). This result did not apply when analysis was restricted to laboratories with 80% or more brachial procedures. Risk was not altered by heparin. Thus, a prospective, multicenter analysis of complications reveals low risk of coronary arteriography but significant difference between two techniques.

Adult↗