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Biomedical subjects

J M Gore

Publications and source records attributed to J M Gore.

At least 109 records · Page 6Linked to original sources

Adjunctive use of beta-adrenergic blockers, calcium antagonists and other therapies in coronary thrombolysis.

The availability of thrombolytic agents for use in the treatment of acute myocardial infarction is an important step in the management of a common, often debilitating, and potentially lethal disorder. However, despite the proven benefits of coronary thrombolysis, the importance of adjunctive treatment modalities is being increasingly recognized. Beta-adrenergic blockers, calcium antagonists, nitrates, magnesium, and angiotensin-converting enzyme inhibitors each exert favorable cardiovascular properties that may offer additional benefits. Clinical trials combining thrombolytic and adjunctive pharmacologic agents offer hope for further advances in the treatment of acute myocardial infarction.

Adrenergic beta-Antagonists↗

Selective versus routine predischarge coronary arteriography after therapy with recombinant tissue-type plasminogen activator, heparin and aspirin for acute myocardial infarction. TIMI II Investigators.

To ascertain whether predischarge arteriography is beneficial in patients with acute myocardial infarction treated with recombinant tissue-type plasminogen activator (rt-PA), heparin and aspirin, the outcome of 197 patients in the Thrombolysis in Myocardial Infarction (TIMI) IIA study assigned to conservative management and routine predischarge coronary arteriography (routine catheterization group) was compared with the outcome of 1,461 patients from the TIMI IIB study assigned to conservative management without routine coronary arteriography unless ischemia recurred spontaneously or on predischarge exercise testing (selective catheterization group). The two groups were similar with regard to important baseline variables. During the initial hospital stay, coronary arteriography was performed in 93.9% of the routine catheterization group and 34.7% of the selective catheterization group (p less than 0.001), but the frequency of coronary revascularization (angioplasty or coronary artery bypass surgery) was similar in the two groups (24.4% versus 20.7%, p = NS). Coronary arteriograms showed a predominance of zero or one vessel disease (stenosis greater than or equal to 60%) in both groups (routine catheterization group 73.1%, selective catheterization group 61.3%). During the 1st year after infarction, rehospitalization for cardiac reasons and the interim performance of coronary arteriography were more common in the selective catheterization group (37.9% versus 27.6%, p = 0.007 and 28.6% versus 11.6%, p less than 0.001, respectively); however, the interim rates of death, nonfatal reinfarction and performance of coronary revascularization procedures were similar. At the end of 1 year, coronary arteriography had been performed one or more times in 98.9% of the routine catheterization group and 59.4% of the selective catheterization group (p less than 0.001), whereas death and nonfatal reinfarction had occurred in 10.2% versus 7.0% (p = 0.10) and 8.6% versus 9.0% (p = 0.87), respectively. Because the selective coronary arteriography policy exposes about 40% fewer patients to the small but finite risks and inconvenience of the procedure without compromising the 1 year survival or reinfarction rates, it seems to be an appropriate management strategy.

Aged↗

Early tPA treatment and aeromedical transport of patients with acute myocardial infarction.

Over a 2-year period 192 patients with acute myocardial infarction (AMI) were transported by helicopter and treated with recombinant tissue-plasminogen activator (tPA). All patients were entered into the Thrombolysis in Myocardial Infarction-Phase II (TIMI II) trial. Eighty-two of these patients were treated with tPA after aeromedical transport to a tertiary care center. One hundred ten patients had tPA treatment initiated by the flight crew prior to transport. The flight crews initiated therapy 28 +/- 11 minutes after arrival at the sending hospital. The post-flight treated patients received the tPA bolus 82 +/- 20 minutes after arrival at the sending hospital (P less than .0001), and 41 +/- 18 minutes after arrival at the receiving hospital (P less than .0001). Based on enzyme and electrocardiographic changes, all patients in the study had a confirmed diagnosis of AMI before discharge. Patients with inferior myocardial infarction (MI) treated with tPA in-flight were more likely to suffer from bradycardia and hypotension requiring atropine injection during transport than the post-flight treated patients or in-flight treated patients with anterior MI. There was no in-flight mortality in either group. Our experience indicates that patients with AMI can be transported safely during tPA therapy. Also, a trained team whose sole responsibility is the early evaluation and initiation of therapy in a patient with AMI can function as accurately and significantly more rapidly than tertiary care emergency department and ICU personnel following identical protocols.

Aged↗

Prognosis following interventional therapy for acute myocardial infarction: utility of dipyridamole thallium scintigraphy.

A variety of methods for risk stratification after acute myocardial infarction have been successfully employed, however, little attention has been focused on patients who have received reperfusion therapy. The present report examines the utility of dipyridamole thallium scintigraphy in the prediction of late cardiac death or recurrent myocardial infarction in patients who have received thrombolytic therapy. Prospectively, 71 patients who presented with myocardial infarction and were treated with recombinant tissue plasminogen activator (and frequently percutaneous transluminal coronary angioplasty) were enrolled in the study. The primary end points during the follow-up period of nearly 2 years were recurrent infarction or death, which occurred in 10 patients. Although cardiac events were significantly related to either the performance of late myocardial revascularization or the presence of a residual coronary artery stenosis at discharge, no scintigraphic variable was found to be predictive of myocardial infarction or death. Thus, this report is the first to suggest limitation of scintigraphic techniques with regard to prognostic value in myocardial infarction survivors treated with reperfusion techniques. This selected population may have physiologic differences as compared with post-infarction studies performed before the advent of thrombolytic agents. Caution is therefore advised in extrapolating results of earlier reports to the ever increasing percentage of patients receiving recannalization therapy.

Adult↗

Intracerebral hemorrhage, cerebral infarction, and subdural hematoma after acute myocardial infarction and thrombolytic therapy in the Thrombolysis in Myocardial Infarction Study. Thrombolysis in Myocardial Infarction, Phase II, pilot and clinical trial.

In the Thrombolysis in Myocardial Infarction, Phase II pilot and clinical trial, 908 patients [326 (35.9%) in the pilot study and 582 (64.0%) in the randomized study] were treated with 150 mg recombinant tissue-type plasminogen (rt-PA) activator in combination with heparin and aspirin, and 3,016 patients [64 (2.1%) in the pilot study and 2,952 (97.9%) in the randomized study] were treated with 100 mg rt-PA in combination with heparin and aspirin. Adverse neurological events occurred in 23 patients treated with 150 mg rt-PA (2.5%) [nine cerebral infarctions (1.0%), 12 intracerebral hemorrhages (1.3%), and two subdural hematomas (0.2%)] and in 33 patients treated with 100 mg rt-PA (1.1%) [20 cerebral infarctions (0.7%), 11 intracerebral hemorrhages (0.4%), and two subdural hematomas (0.1%)]. The difference in adverse neurological events observed comparing the two rt-PA regimens was primarily due to a higher frequency of intracerebral bleeding among patients treated with 150 mg rt-PA (1.3% versus 0.4%, p less than 0.01). Patients with recent (within 6 months) histories of stroke were not eligible for the study, and patients with any history of cerebrovascular disease were declared ineligible early in the study. The small number of patients (89, or 2.3%) with any history of neurological disease, intermittent cerebral ischemic attacks, or stroke who were enrolled before the stricter eligibility criteria were imposed or on the basis of incomplete baseline information experienced an increased frequency of intracerebral hemorrhage compared with patients without such histories (3.4% versus 0.5%). Mortality at 6 weeks after presentation among 23 patients who had intracerebral hemorrhage was 47.8%. Intracerebral hemorrhage is a severe but infrequent complication of rt-PA therapy for acute myocardial infarction. The combined frequency of intracerebral hemorrhage, subdural hematoma, and cerebral infarction after treatment with 100 mg rt-PA is comparable to that observed in other trials with thrombolytic agents in acute myocardial infarction.

Cerebral Hemorrhage↗

Cardiovascular therapies in the 1990s. An overview.

Cardiovascular medicine has evolved steadily over the past two decades. Inspired by progressive declines in the overall incidence and mortality rates from cardiovascular diseases, emphasis has been placed on 3 specific areas: prevention, early diagnosis, and aggressive intervention. During the decade spanning the 1980s, impressive strides were made in many areas--diagnostic and therapeutic alike. However, an observed reduction in patient mortality stemming from acute myocardial infarction was particularly gratifying. Clearly, the large scale use of thrombolytic therapy and postinfarction strategies designed to prevent reinfarction, limit ventricular dilation, and reduce cardiac death figured prominently. Despite these encouraging facts, however, coronary heart disease remains the leading cause of death in Western society, and thrombolytic therapy is still not being utilised by the medical community to its full potential. Furthermore, adjuvant therapy, during both the early and the late phases of acute myocardial infarction, is being instituted inconsistently, and at times haphazardly. Arrhythmia management and the prevention of sudden cardiac death require further investigation, as does the treatment of chronic congestive heart failure, and the prevention of coronary atherosclerosis. This overview provides a state-of-the-art review and look into the future of 5 critical areas: acute myocardial infarction, adjuvant treatment strategies for acute myocardial infarction, cardiac arrhythmias, chronic congestive heart failure, and hyperlipidaemias.

Cardiovascular Diseases↗

Intravenous nitroglycerin-induced heparin resistance: a qualitative antithrombin III abnormality.

An ability of intravenous nitroglycerin to interfere with the anticoagulant properties of intravenous heparin would have profound clinical implications. To investigation nitroglycerin-heparin interactions, the following pilot study was performed. Patients (N = 18) admitted to the coronary care unit with a diagnosis of either acute myocardial infarction or unstable angina were divided into four treatment groups: (1) intravenous nitroglycerin and intravenous heparin; (2) intravenous nitroglycerin alone; (3) intravenous heparin alone; or (4) neither intravenous nitroglycerin nor intravenous heparin. Serial determinations of activated partial thromboplastin time (APTT), serum heparin concentration, antithrombin III (ATIII) antigen (ATA), and ATIII activity (ATC) were obtained over a 72-hour period. Overall, patients receiving intravenous nitroglycerin did not differ significantly from other patients in APTT, heparin dose, heparin concentration, ATA, ATC, or ATA/ATC ratio (ATR). However, patients receiving intravenous nitroglycerin at a rate exceeding 350 micrograms per minute had a lower APTT (p less than 0.05), lower ATC (p = 0.02), higher ATR (p = 0.004), and a larger heparin dose requirement than patients receiving lower infusion rates. ATR correlated directly (r = 0.91; p less than 0.05) and ATC inversely (r = -0.78; p less than 0.05) with the intravenous nitroglycerin dose. Serum heparin concentration did not correlate with the intravenous nitroglycerin dose. Intravenous nitroglycerin-induced heparin resistance occurs at a critical nitroglycerin dose. A nitroglycerin-induced qualitative ATIII abnormality may be the underlying mechanism.

Adult↗

Impact of atrial fibrillation on the in-hospital and long-term survival of patients with acute myocardial infarction: a community-wide perspective.

As part of an ongoing community-wide study examining changes over time in the incidence and survival rates of 4108 patients hospitalized with validated acute myocardial infarction (MI) in 16 hospitals in the Worcester, Massachusetts, metropolitan area during calendar years 1975, 1978, 1981, 1984, and 1986, we examined changes over time in the proportion of patients with acute MI developing atrial fibrillation (AF) and the impact of AF on in-hospital and long-term survival for up to a 10-year follow-up period. The overall percentage of patients with AF complicating acute MI was 16.0%; this proportion increased over time from 13.3% in 1975 to 14.8% in 1978, 14.9% in 1981, 20.3% in 1984, and to 17.7% in 1986. Patients with AF experienced consistently higher in-hospital case fatality rates than MI patients without AF overall (27.6% versus 16.6%), as well as during each of the 5 years under study. The independent effect of AF on in-hospital survival was not upheld, however, when a variety of potentially confounding prognostic factors were controlled for in a multivariate analysis resulting in an adjusted odds ratio (OR) of 1.18 (95% confidence interval 0.90, 1.52). Among discharged hospital patients, while the crude long-term survival rate for patients with AF was poorer than that of patients without AF for the combined as well as for individual study periods, similar to the in-hospital findings the independent effect of AF on long-term prognosis was not upheld after use of a multivariate analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗

Comparison of immediate invasive, delayed invasive, and conservative strategies after tissue-type plasminogen activator. Results of the Thrombolysis in Myocardial Infarction (TIMI) Phase II-A trial.

To assess the value and timing of percutaneous transluminal coronary angioplasty (PTCA) after thrombolytic therapy for acute myocardial infarction (AMI), 586 patients in the Thrombolysis in Myocardial Infarction Study Phase II-A were randomized among three treatment strategies, one using immediate coronary arteriography followed by PTCA if appropriate (immediate invasive strategy group, n = 195), a second that deferred angiography and PTCA for 18-48 hours (delayed invasive strategy group, n = 194), and a third, more conservative, approach in which PTCA was used only if ischemia occurred spontaneously or at the time of predischarge exercise testing (conservative strategy group, n = 197). Predischarge contrast left ventricular ejection fraction, the primary study end point, was similar among the patients in all three treatment groups and averaged 49.3%. The finding of a patent infarct-related artery at the time of predischarge arteriography was equally common among the patients in the three groups (mean, 83.7%); however, the mean residual infarct artery stenosis was greater in the patients in the conservative strategy group (67.2%) as compared with the patients in the immediate invasive (50.6%) and the delayed invasive strategy groups (47.8%) (p less than 0.001). Immediate invasive strategy led to a higher rate of coronary artery bypass graft surgery (CABG) after PTCA (7.7%) than did delayed invasive and conservative strategies (2.1% and 2.5%, respectively; p less than 0.01). Furthermore, among patients not undergoing CABG during the first 21 days, blood transfusion of more than 1 unit was used in 13.8% of the patients in the immediate invasive strategy group, 3.1% of the patients in the delayed invasive strategy group, and 2.0% of the patients in the conservative strategy group (p less than 0.001). At 1-year follow-up, the three treatment groups had similar cumulative rates of mortality (8.7%, pooled over all groups), fatal and nonfatal reinfarction (8.5%), combined death and reinfarction (14.5%), and CABG (17.2%), although the cumulative performance rate of PTCA remained higher in the invasive groups (immediate invasive strategy group, 75.8%; delayed invasive strategy group, 64.3%; and conservative strategy group, 23.9%; p less than 0.001). Thus, because conservative strategy achieves equally good short- and long-term outcome with less morbidity and a lower use of PTCA, it seems to be the preferred initial management strategy.

Aged↗

Thrombolytic therapy and the nursing profession. Results of a statewide survey.

A statewide survey of 624 nurses in 92 hospitals in Massachusetts indicates that recombinant tissue-type plasminogen activator and streptokinase are the most widely available thrombolytic agents. Nurses play an active role in drug reconstitution and administration, but only 20% of the total respondents participate consistently in screening procedures. The majority of patients were informed about the risks and benefits of treatment before initiation of therapy. Nurses reported their major management concern was internal bleeding, with cost of treatment being a minor concern.

Adult↗