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Biomedical subjects

J H Horgan

Publications and source records attributed to J H Horgan.

At least 19 recordsLinked to original sources
PubMed2000

Acute psychological stress decreases plasma tissue plasminogen activator (tPA) and tissue plasminogen activator/plasminogen activator inhibitor-1 (tPA/PAI-1) complexes in cardiac patients.

Tissue plasminogen activator (tPA) promotes fibrinolysis, and impaired fibrinolysis is associated with atherosclerosis and thrombosis. Plasminogen activator inhibitor-1 (PAI-1) inhibits t-PA expression. The effects of acute laboratory stressors on tPA and tPA/PAI-1 complexes were assessed in a sample of 11 cardiac patients. Participants were randomly assigned to either a stress or relaxation condition at time 1, and the alternative condition at time 2. Blood samples were taken before (pre) and after (post) each session and participants completed a battery of psychological questionnaires. Two-way repeated-measures analysis of variance revealed a statistically significant decrease in tPA (P = 0.01) and tPA-PAI-1 complexes (P = 0.04) during the mental stress condition. Anger-in had a strong relationship to decreases in tPA/PAI-1 levels in the stress condition (r = 0.68, P < 0.05). Relaxation had no significant effect on tPA and tPA/PAI-1 levels. These data suggest that decreased fibrinolysis mediates the relationship between mental stress and atherosclerosis.

Coronary Disease↗
PubMed1999

One-year survival among patients with acute myocardial infarction complicated by cardiogenic shock, and its relation to early revascularization: results from the GUSTO-I trial.

BACKGROUND: Although 30-day survival is increased in patients with acute myocardial infarction complicated by cardiogenic shock who undergo coronary revascularization, the longer-term outcome in such patients and the duration of benefit from revascularization are unknown. METHODS AND RESULTS: We analyzed 30-day survivors of acute myocardial infarction in the Global Utilization of Streptokinase and Tissue-Plasminogen Activator for Occluded Coronary Arteries (GUSTO-I) trial and identified 36 333 who had not had cardiogenic shock (systolic blood pressure <90 mm Hg for >/=1 hour, group 1) and 1321 patients who had shock (group 2). Group 2 patients were older and sicker. At 1 year, 97.4% of group 1 patients were alive versus 88.0% of group 2 (P=0.0001). Among group 2 patients, 578 (44%) had undergone revascularization within 30 days (group 2A) and 728 (56%) had not (group 2B). Revascularization was not required by protocol but was selected by the attending physicians. At 1 year, 91.7% of group 2A patients were alive versus 85.3% of group 2B (P=0.0003). With the use of multivariable logistic regression analysis to adjust for differences in baseline characteristics of shock patients alive at 30 days, revascularization within 30 days was independently associated with reduced 1-year mortality (odds ratio 0.6, [95% confidence interval 0.4, 0.9], P=0.007). CONCLUSIONS: Most patients (88%) with acute myocardial infarction complicated by cardiogenic shock who are alive at 30 days survived at least 1 year. Shock patients who underwent revascularization within 30 days had improved survival at 1 year compared with shock patients who did not receive revascularization, even after adjustment for differences in baseline characteristics between the 2 groups.

Aged↗
PubMed1999

Psychosocial outcome assessments for use in cardiac rehabilitation service evaluation: a 10-year systematic review.

A variety of measures are currently used to assess psychosocial outcome (quality of life) in cardiac rehabilitation programmes. However, there is no consensus on the most appropriate instruments to use. Instruments that are not sufficiently responsive to change in cardiac populations are unsuitable as audit tools as they underrepresent the benefits of programme attendance. To identify the most responsive instruments in cardiac rehabilitation populations a systematic overview of studies for the 10-year period 1986-1995 was conducted. The following databases were searched: Medline, Psychlit, Cinahl and Sociofile and 32 relevant studies were identified. The effect size statistic (a comparison of the magnitude of change to the variability in baseline scores) was used to determine those instruments most responsive to change. The following instruments were identified as being responsive in more than one study: Beck Depression Inventory, Global Mood Scale, Health Complaints Checklist, Heart Patients Psychological Questionnaire and Speilberger State Anxiety Inventory. There is little consensus on psychosocial evaluation instrument use in the cardiac rehabilitation literature. A number of measures show significant potential for routine outcome assessment. Formal assessment of these instruments is recommended to inform final recommendations about instrument selection for audit and evaluation purposes in cardiac rehabilitation.

Cardiac Rehabilitation↗
PubMed1996

Relation of increased arterial blood pressure to mortality and stroke in the context of contemporary thrombolytic therapy for acute myocardial infarction. A randomized trial. GUSTO-I Investigators.

BACKGROUND: Despite concern that hypertension increases the risk for intracranial hemorrhage during thrombolysis for acute myocardial infarction, the exact nature of the risk remains unclear. OBJECTIVE: To assess the effects of previous hypertension and blood pressure at study entry on the outcomes of patients who had acute myocardial infarction and received thrombolysis. DESIGN: Randomized trial. SETTING: 1081 hospitals in 15 countries. PATIENTS: 41,021 patients who had myocardial infarction accompanied by ST-segment elevation and who presented to hospitals within 6 hours of symptom onset. INTERVENTION: One of four thrombolytic regimens. MAIN OUTCOME MEASURES: Mortality, stroke subtypes, and death plus disabling stroke in patients with previous hypertension and as functions of blood pressure at entry. Logistic regression analysis of relations among blood pressure at entry, baseline characteristics, and treatment effects. RESULTS: The incidence of total stroke and intracranial hemorrhage increased as systolic blood pressure at entry increased and was particularly high for systolic pressures of about 175 mm Hg or more (incidence of total stroke, 3.4% compared with 1.17% for pressures between 100 and 124 mm Hg). Patients who had systolic blood pressure of 175 mm Hg or more at entry and who received accelerated alteplase therapy had a lower rate of death within 30 days (4.3% compared with 7.8%; P = 0.044) and a lower rate of death plus disabling stroke (4.9% compared with 8.9%; P = 0.031) than patients treated with streptokinase, despite having higher rates of total and hemorrhagic stroke (incidence of hemorrhagic stroke, 2.3% compared with 1.5%). Assumptions based on previous trials and rates of stroke from the GUSTO-1 (Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries) trial suggest that in hypertensive patients with low risk for death from cardiac causes (no previous infarction, Killip class I), the risk-to-benefit ratio with thrombolysis is about unity, with about 13 lives saved per 1000 persons treated at the risk of about 13 intracranial hemorrhages. CONCLUSIONS: Patients with myocardial infarction and very elevated blood pressure who have thrombolysis and risk for stroke is higher in the former group. Future studies should assess 1) the risk-to-benefit ratio of thrombolysis in these patients, especially those at low risk for death from cardiac causes, and 2) whether decreasing elevated blood pressure before thrombolysis reduces the incidence of stroke without increasing mortality rates.

Aged↗
PubMed1996

Early discharge in the thrombolytic era: an analysis of criteria for uncomplicated infarction from the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO) trial.

OBJECTIVES: This study sought to readdress the definition of uncomplicated myocardial infarction and to apply clinical criteria for early discharge of such patients in the thrombolytic era. BACKGROUND: Previous studies proposed early hospital discharge at day 7 to 10 after acute myocardial infarction. The potential for earlier discharge of patients with uncomplicated infarction after thrombolysis remains undemonstrated. METHODS: We defined "uncomplicated infarction" a priori as the absence of death, reinfarction, ischemia, stroke, shock, heart failure (Killip class > 1), bypass surgery, balloon pumping, emergency catheterization or cardioversion or defibrillation in the first 4 hospital days. We applied this definition to 41,021 patients in the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO-I) trial. We examined death at 30 days and 1 year and rates of in-hospital reinfarction, heart failure, recurrent ischemia, shock and stroke in the uncomplicated and complicated groups created by application of our definition. We also assessed lengths of hospital and cardiac care unit stay. RESULTS: Application of our clinical criteria yielded 23,497 (57.3%) patients in the uncomplicated group at day 4 with a very low risk of death and in-hospital complications: 30-day mortality 1%, reinfarction 1.7%, heart failure 2.6%, recurrent ischemia 6.7%, shock 0.4% and stroke 0.2%. One-year mortality was 3.6%. The median hospital stay was 9 days (7, 12 [25th, 75th percentiles, respectively]), and the median cardiac care unit stay 3 days (3, 5). CONCLUSIONS: Simple clinical characteristics can identify a very low risk post-myocardial infarction population by hospital day 4. Use of these criteria for early discharge planning could substantially reduce length of stay for patients with uncomplicated acute myocardial infarction.

Aged↗
PubMed1995

Contemporary reperfusion therapy for cardiogenic shock: the GUSTO-I trial experience. The GUSTO-I Investigators. Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries.

OBJECTIVES: This study sought to examine the incidence, temporal profile and clinical implications of shock in a large trial of thrombolytic therapy for acute myocardial infarction. BACKGROUND: Despite advances in the treatment of acute ischemic syndromes, cardiogenic shock remains associated with significant morbidity and mortality. METHODS: Patients who presented within 6 h of symptom onset were randomized to four treatment strategies: 1) streptokinase plus subcutaneous heparin; 2) streptokinase plus intravenous heparin; 3) accelerated recombinant tissue-type plasminogen activator (rt-PA) plus intravenous heparin; or 4) streptokinase and rt-PA plus intravenous heparin. The primary end point was 30-day all-cause mortality. RESULTS: Shock occurred in 2,972 patients (7.2%): 315 (11%) had shock on arrival, and 2,657 (89%) developed shock after hospital admission. Reinfarction occurred in 11% of patients who developed shock compared with 3% of patients without shock. The mortality rate was significantly higher in patients who presented with (57%) or developed (55%) shock than in those without shock (3%) (p < 0.001). Shock developed significantly less frequently in patients receiving rt-PA. There were fewer deaths in patients who presented with shock and were treated with streptokinase plus intravenous heparin or who developed shock and were treated with streptokinase plus subcutaneous heparin. Patients who developed shock had a significantly lower 30-day mortality rate if angioplasty was performed. CONCLUSIONS: Because cardiogenic shock occurred most often after admission and with recurrent ischemia and reinfarction, recognizing signs of incipient shock may improve outcome. Fewer patients treated with rt-PA developed shock, yet those developing shock had the same high mortality rate as those presenting with shock, regardless of treatment. Only angioplasty was associated with a significantly lower mortality rate.

Aged↗
PubMed1994

Fluid replacements after squash: an analysis of the effects of several fluid regimens on exercise-related metabolic changes.

We studied the effects of several fluid replacements taken after squash on exercise-related metabolic responses. 12 subjects played 5 games and after each game were assigned one of the following, receiving a different one each time: (1) no fluid replacement, or 500 ml of (2) water, (3) electrolyte solution, (4) glucose solution or (5) a glucose/electrolyte 'sports' drink. Circulating levels of lactate, free fatty acids, glucose, potassium, sodium and plasma osmolality were measured at rest and at 5, 15, 30 and 60 min after games. There were significant changes over time for all measured variables (p < 0.001). The only effect of these drinks was by the glucose-containing drinks, which resulted in significant elevation of blood glucose levels (p < 0.001); no effects on circulating electrolyte levels were demonstrated. In conclusion, while fluid replacements may increase glucose levels, electrolyte levels are not affected by drinks which are commonly used after squash.

Adult↗
PubMed1993

Return to work following coronary artery bypass surgery or percutaneous transluminal coronary angioplasty.

Return to work (RTW) and other treatment outcomes of coronary artery bypass graft (CABG) and percutaneous transluminal coronary angioplasty (PTCA) patients were compared. Consecutive patients at one centre (n = 112 CABG and 119 PTCA patients) were interviewed 6-18 months following treatment (groups were similar in sex and social class). Pre-treatment employment levels were similar (41 and 38% for CABG and PTCA groups, respectively). PTCA patients were more likely to smoke, have angina, have less advanced cardiovascular disease and have been advised to stop working for medical reasons pre-treatment. Post-treatment levels of employment increased significantly. RTW rates were similar for CABG and PTCA groups (59 and 68% respectively). Both groups had reduced smoking to similar levels. The PTCA group continued to have higher levels of angina. For those without angina, PTCA patients were significantly more likely to return to work (73 vs 55%, P < 0.01). Both CABG and PTCA resulted in increased employment post-treatment.

Angina Pectoris↗
PubMed1993

Exercise-related potassium and free fatty acid level changes in coronary artery disease. Responses after moderate intensity training.

Exercise produces changes in circulating levels of potassium and free fatty acids which may provoke arrhythmias in patients with coronary artery disease. Twenty patients participating in 6 weeks of training were studied; 9 of these patients took part in 4 more weeks of training and a third exercise test. After 6 weeks, potassium levels were higher at submaximal levels of exercise, free fatty acid levels were reduced at rest, and at 5, 15, and at 30 min post-exercise. Norepinephrine levels were reduced at submaximal work loads after 6 weeks and increased at maximal work loads. The extra 4 weeks had no additive effect on these metabolic changes. Participation by coronary artery disease patients in a short-term, moderate intensity, exercise training program increases potassium levels at submaximal work loads and reduces levels of free fatty acids at rest and after exercise. The arrhythmogenic relevance of these findings deserves further consideration.

Aged↗
PubMed1992

The effects of captopril on training in patients with ischemic heart disease.

We studied a group of 30 patients to determine the effect of captopril on the exercise training response after a period of training in patients with ischemic heart disease but without cardiac failure. The study was a double-blind placebo-controlled comparison of captopril and placebo. The patients studied were 28 men and 2 women, mean age 53.6 +/- 6.9 years. All were 8 to 12 weeks postmyocardial infarction or coronary artery bypass surgery. These patients underwent an organized exercise training program consisting of exercise training sessions 3 times weekly for a period of 8 weeks. On commencement and completion of the program patients were assessed for exercise tolerance using submaximal exercise stress testing. Patients were assessed in the untreated state. Both groups showed a statistically significant training effect with increased exercise duration, decreased heart rate for equal workload, increased energy expenditure, and reduced functional aerobic impairment. There was no statistically significant change in systolic blood pressure, but the captopril group alone showed a significant reduction in diastolic blood pressure (p less than 0.001). The change in heart rate at rest over the 8-week period was not significant in both groups. In summary, this study shows that treatment with captopril does not affect the exercise training response in patients with ischemic heart disease undergoing an organized exercise training program.

Blood Pressure↗
PubMed1992

The effects of verapamil on training in patients with ischemic heart disease.

Verapamil is a calcium-channel blocking agent with antianginal and antiarrhythmic properties that have been widely studied. Its myocardial depressant effect is well known. The purpose of this study was to examine the effects of verapamil on the training response in patients with ischemic heart disease. The study group consisted of 41 male patients with a mean age of 53.3 +/- 7.2 years who had suffered a myocardial infarction or had undergone coronary artery bypass surgery 8 to 12 weeks previously. They were chosen on a consecutive basis from eligible patients entering a cardiac rehabilitation program. With use of a double-blind technique, 21 patients were assigned to receive verapamil, 120 mg three times daily, while the other 20 were given an identical placebo. Each patient underwent exercise stress testing in the untreated state to permit comparison between tests performed on commencement and completion of training. The training effect was determined by comparing exercise response before and after the eight-week program. There was an increase in exercise duration (p less than 0.001) and a decrease in functional aerobic impairment (p less than 0.001), without difference between the two groups. Energy expenditure increased in both groups, but the highest level was achieved by those receiving active treatment (p less than 0.02). Heart rate for equal workload was significantly reduced after training (p less than 0.001), although this was lower in the placebo patients (p less than 0.001) and the patients who had a recent myocardial infarction (p less than 0.01). It appears that treatment with verapamil does not impair the development of a training effect in patients with ischemic heart disease who are undergoing organized training.

Anaerobic Threshold↗
PubMed1992

Metabolic changes during serial squash matches in older men.

We have previously reported dramatic changes in heart rate and blood biochemistry in older men during and shortly after competitive squash. In this study we sought to determine whether these changes are attenuated or exaggerated during tournament matches played in rapid succession. Ten veteran (greater than 45 yrs) players were studied during three competitive matches played over a 36-hr period. Squash was associated with significant changes in heart rate and circulating concentrations of catecholamines, lactate, free fatty acids, and potassium. These changes were of equal magnitude and in some cases tended to be exaggerated during the second and third matches. These data confirm the acute changes in cardiac function and metabolism that occur during competitive squash and suggest that these responses are not down-regulated but may in fact be accentuated during sequential tournament matches.

Aging↗
PubMed1991

Medical management of acute myocardial infarction in Ireland: information from the Second International Study of Infarct Survival (ISIS-2).

We report the management of the 831 patients from 18 hospitals which constituted the Irish component of the 17,183 subjects enrolled in the ISIS-2 trial which studied the effects of streptokinase infusion and aspirin therapy given to patients presenting within 24 hours of the onset of suspected acute myocardial infarction. 34% of Irish patients (IP) presented for treatment within 4 hours of the development of symptoms. This compared to 44% of the overall group (OG) (p less than 0.001). This represented the lowest percentage of patients presenting within 4 hours in any of the participating countries. The mean delay time from onset of symptoms was 7.9 hours in IP compared to 6.9 in OG (p less than 0.001). The mean delay time in Ireland was longer than the mean delay time in any of the participating countries. The mean age and systolic blood pressure at presentation was similar in both groups. It was planned to treat 12% IP with aspirin compared to 10% OG (p-NS), and 71% IP with subcutaneous heparin compared with 47% OG (p less than 0.001). Intravenous heparin was planned treatment in 20% IP and 24% OG (p less than 0.01). Planned oral anticoagulant therapy was similar in both groups (p-NS). Planned use of intravenous betablockers occurred in only 2% IP and 6% OG (p less than 0.001). 9% IP and 22% OG received steroids before streptokinase infusion (p less than 0.001). 65% IP and 47% OG received subcutaneous heparin (p less than 0.001). The use of intravenous heparin and oral anticoagulants was similar in IP and OG (p-NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1990

Early detection of acute myocardial infarction: additional diagnostic information from serum concentrations of myoglobin in patients without ST elevation.

The value of the 12 lead electrocardiogram, serum total creatine kinase, creatine kinase MB isoenzyme, and myoglobin for the early detection of infarction was evaluated within one hour of admission to the coronary care unit in 82 consecutive patients with suspected myocardial infarction. The 51 patients in whom infarction was diagnosed during the first 24 hours after admission had a higher prevalence of ST elevation (64% v 11%), higher median serum myoglobin (136 micrograms/l v 34 micrograms/l), higher serum creatine kinase (77 IU/l v 34 IU/l), and higher MB isoenzyme (7 IU/l v 4 IU/l) than those in whom it was not. Stepwise logistic regression analysis in 70 patients in whom the electrocardiogram and serum myoglobin were suitable for analysis showed that serum myoglobin was the variable most closely associated with infarction, and contributed additional diagnostic information when ST elevation was entered into the model first. Serum myoglobin remained associated with myocardial infarction when patients who had had symptoms for less than six hours were analysed. An algorithm based on a rapid agglutination test for myoglobin and ST elevation on the electrocardiogram gave an accurate diagnosis in 82% of patients. This approach gave early and rapid recognition of acute myocardial infarction and warrants further examination.

Clinical Enzyme Tests↗
PubMed1989

Heart rate and metabolic response to competitive squash in veteran players: identification of risk factors for sudden cardiac death.

We studied 10 older males during a competitive game and the early post-exercise period to define the metabolic response to squash in veteran players. For comparison, all subjects were also studied during exhaustive treadmill exercise. Squash caused a dramatic increase in heart rate (150%), and circulating levels of noradrenaline (164%), adrenaline (93%), lactate (202%) and free fatty acids (67%). These effects were independent of haemoconcentration. The early post-exercise period (5 min) was characterized by persistent elevation of plasma catecholamines, lactate, and free fatty acids, hypokalaemia and ventricular arrhythmias. The heart rate and metabolic responses to squash were similar in pattern and magnitude to those observed during treadmill exercise, highlighting the strenuous nature of squash as a recreation sport. While these changes may represent appropriate physiological adaptation to exercise in health, each has been implicated in the pathogenesis of fatal ventricular arrhythmias in subjects with ischaemic heart disease. These data support the contention that squash may be an inappropriate form of exercise for older men with coronary artery disease.

Arrhythmias, Cardiac↗