Lipoprotein (a) is increased in acute coronary syndromes (unstable angina pectoris and myocardial infarction), but it is not predictive of the severity of coronary lesions

Lipoprotein (a) [Lp(a)] concentrations were determined in 365 patients undergoing coronary angiography for stable angina (n = 159), unstable angina (n = 99), recent myocardial infarction (n = 45), and nonischemic heart disease (cardiomyopathy or valvular disease, n = 62, non-IHD). Mean +/- SD and median Lp(a) concentrations in stable angina (29.9 +/- 29.2;22 mg/dl) did not differ from those in non-IHD (26.9 +/- 26.3; 17), but were significantly lower than in patients with unstable angina (52.7 +/- 36.6; 58) and myocardial infarction (44.8 +/- 36.4; 34) (p < 0.01). Coronary angiography revealed that 261 patients, including 4 patients in the non-IHD group, had significant (> or = 50%) coronary lesions. Lp(a) was higher in patients with (41 +/- 35; 32) than in those without (28 +/- 27; 19) angiographic evidence of significant coronary stenosis (p < 0.05) and showed a weak univariate correlation with the angiographic index (Total Score) of the severity of the disease (r = 0.106;p < 0.05). However, in the subgroup of 303 patients with stable/unstable angina or myocardial infarction, Lp(a) was predictive neither of angiographic presence nor of severity of coronary disease. Patients were then ranked according to the Total Score values. Among patients with comparable angiographic severity of coronary artery disease, Lp(a) appeared to be remarkably higher in patients with acute ischemic syndromes (unstable angina, myocardial infarction) than in patients with stable angina. In conclusion, Lp(a) was roughly twice as high in acute (unstable angina, myocardial infarction) than in chronic (stable angina) ischemic syndromes, but there was no difference between chronic stable angina and non-IHD.(ABSTRACT TRUNCATED AT 250 WORDS)

Perfusional and metabolic effects of nisoldipine as shown by positron emission tomography after acute myocardial infarction

After myocardial infarction, regional dysfunction can occur in viable myocardial regions because of the presence of baseline hypoperfusion. Recent evidence suggests that these areas may maintain a residual perfusion reserve. The aim of the present study was to evaluate whether oral nisoldipine can increase regional myocardial blood flow (MBF) in dyssynergic but viable myocardium after myocardial infarction. Patients with isolated left anterior descending coronary stenosis were studied 1 month after the first myocardial infarction. Patients underwent [18F]fluorodeoxyglucose imaging, and MBF was measured, using positron emission tomography and [13N]ammonia, at baseline and following dobutamine administration (10 micrograms/kg/min over 5 minutes). MBF measurements were repeated 24 hours after nisoldipine (10 mg twice daily). Preliminary results suggest that necrotic areas showed the largest reduction in baseline MBF. Dyssynergic-viable regions showed a reduced resting MBF but maintained a residual perfusion reserve in response to inotropic stimulation. Thus, nisoldipine selectively improved basal perfusion in dyssynergic-viable myocardium.

The patient's perception of his own quality of life might have an adjunctive prognostic significance in lung cancer

Only 5-10% of patients with lung cancer (LC) can be expected to be cured by radical treatments. In the remaining subjects the potential survival benefit of treatment must be weighed, taking into consideration the possible deterioration of quality of life (QL). Indeed, studies dealing with different aspects of QL are being increasingly reported in LC. In a few of them, the interesting observation was made that the patient-rated QL correlated well with the subsequent clinical outcome. In the present study we analyse 11 items of the Therapy Impact Questionnaire (a new instrument of QL), assessing both disease and therapy impact on physical condition, functional status, concomitant emotional and cognitive factors and social interactions. Questionnaires were completed by 128 consecutive LC patients, who had been seen, in the years 1990 through 1993, either for a newly diagnosed cancer (40 patients), or after a successful operation (15 patients), or during active and/or symptomatic treatment (73 patients). At the time of the QL assessment, a minimal set of demographic and clinical variables was recorded. Univariate tests of survival showed that stage of disease, difficulty at work or doing the housework, weight loss, performance status, difficulty relaxing, having been felt unsure, and tumor cell type were all associated, in decreasing order of significance, with prognosis. QL variables correlated well with each other, but poorly with clinical and demographic variables (an expected exception was the good correlation existing between working capacity/physical autonomy and the corresponding observer evaluation of performance status). This lack of correlations explains how QL variables maintained their significance in multivariate survival analyses. In the best multivariate model, the self-estimated difficulty at work or doing the housework followed the stage of disease, but preceded weight loss as a significant, independent, prognostic determinant. Further studies evaluating several other additional prognostic indicators are needed to better clarify the relative prognostic importance of quality of life.

[Hyperinsulinemia and cardiovascular risk]

A large body of evidence has been accumulating that insulin plays a role in coronary heart disease (CHD). Hyperinsulinemia has been considered a risk factor for CHD according to prospective studies. Cross-sectional studies found an association between hyperinsulinemia and prevalence of CHD, while population studies have shown that populations at increased risk for CHD are hyperinsulinemic. Strong relations between hyperinsulinemia and atherosclerotic coronary lesions have been demonstrated by angiographic studies. It has recently been observed that also patients with microvascular angina are hyperinsulinemic. Several mechanisms have been proposed to explain the role of hyperinsulinemia in the development of atherothrombosis. Hyperinsulinemia is the consequence of insulin resistance, a defect in insulin-mediated glucose uptake. Experimental evidence suggests that insulin has actions that may promote atherosclerosis, which clinical studies suggest the existence of a metabolic syndrome characterized by the presence of major coronary risk factors in which insulin resistance is the common link.

Efficacy of L-propionylcarnitine treatment in patients with left ventricular dysfunction

The effect of L-propionylcarnitine on patients with left ventricular dysfunction (EF < 45%) NYHA class II, symptomatic despite therapy with digitalis and diuretics was evaluated in a phase II parallel, double-blind, randomized, placebo-controlled study. Fifty patients (28 men and 22 women) aged 37-70 years received 1.5 g of L-propionylcarnitine or placebo on a random basis as oral treatment for 6 months. At baseline, during a 7 day placebo run-in period, and during the 6-month treatment bicycle exercise test, M-B mode and Doppler echocardiography, and clinical evaluation (clinical score) were repeatedly performed. The analysis of variance for repeated measurements showed a statistically significant difference (P < 0.01) in the mean value of exercise time between the treatments over the period of the study. There was a final increase of 0.36 min in the placebo group, 1.4 min in the treated group and a minor production of lactate during exercise in the treated group. Left ventricular shortening fraction and left ventricular ejection fraction showed a significant increase in the L-propionylcarnitine group (respectively P < 0.01 and P < 0.0001) whereas no difference was apparent in the placebo group. Stroke volume index and cardiac index showed significant increments in the treated group (P < 0.05) and systemic vascular resistance was lowered (P < 0.05). No haemodynamic variations were observed in the placebo group, and the clinical score showed a significant improvement in the L-propionylcarnitine treated group. In conclusion, L-propionylcarnitine treatment was shown to improve patient symptomatology and effort tolerance.

Effectiveness and safety of a single intravenous bolus injection of tissue-type plasminogen activator in acute myocardial infarction. Bolus Dose-Escalation Study of Tissue-Type Plasminogen Activator (BEST) Investigators

The efficacy of multiple intravenous bolus injections of tissue-type plasminogen activator (t-PA) in inducing rapid coronary recanalization in patients with acute myocardial infarction was previously demonstrated. In this Bolus Dose-Escalation Study of Tissue-Type Plasminogen Activator (BEST), the efficacy of 3 different doses of a single rapid intravenous bolus injection of t-PA (dute-plase, Wellcome Foundation, London) in inducing coronary patency (Thrombolysis In Myocardial Infarction perfusion grade 2 or 3) in 64 patients with acute myocardial infarction presenting less than 6 hours after onset of symptoms was investigated. At 60 minutes after administration of t-PA, the infarct-related coronary artery was patent in 9 of 17 patients (53%; 95% confidence interval [CI] 28 to 77%) after 0.3 MU/kg, in 14 of 23 (61%; 95% CI 39 to 80%) after 0.45 MU/kg and in 10 of 14 (71%; 95% CI 42 to 92%) after 0.6 MU/kg. At 90 minutes after t-PA, coronary patency was present in 9 of 17 cases (53%; 95% CI 28 to 77%) after 0.3 MU/kg, in 12 of 24 (50%; 95% CI 29 to 71%) after 0.45 MU/kg and in 10 of 13 (77%; 95% CI 46 to 95%) after 0.6 MU/kg. One patient in each dose group had a silent reoccluded infarct-related artery by 24 hours, and there were 2 clinical reinfarctions before discharge. No major bleeding events were observed. There were 5 hospital deaths, all unrelated to t-PA. A single intravenous bolus injection of 0.6 MU/kg of t-PA appears to be effective in inducing rapid coronary patency and to be safe in patients with acute myocardial infarction.

Gallopamil and diltiazem: a double-blind, randomized, cross-over trial in effort ischaemia

The aim of this study was to evaluate the efficacy and possibly the mechanism of action of gallopamil and diltiazem in a double-blind crossover trial in patients with effort ischaemia. Twenty male patients (mean age 57 +/- 6 years) with documented coronary atherosclerosis and exercise-induced ischaemia (ST depression greater than or equal to 0.15 mV) completed the study, which consisted of four 7 day periods. At the end of each period a multistage bicycle exercise stress test was performed under placebo (first and third periods) and randomly under gallopamil (50 mg t.i.d.) or diltiazem (90 mg t.i.d.) in the second and fourth periods. Both drugs significantly increased time to ischaemia (0.15 mV ST depression) as compared to placebo, from 7.9 +/- 1.7 min to 8.9 +/- 1.1 min (diltiazem) and 9.1 +/- 1.6 min (gallopamil) with no significant difference between the two drugs, and reduced the maximal extent of ST shift from 0.18 +/- 0.08 mV to 0.13 +/- 0.04 mV (diltiazem) and 0.12 +/- 0.05 mV (gallopamil). Analysis of the results from the whole population showed that the beneficial effect did not appear to be related to any specific parameter. Individual analysis showed that 13/20 patients under gallopamil and 13/20 under diltiazem increased time to ischaemia, while this was unchanged or reduced in the remainder. A positive correlation between changes in time to ischaemia and changes in rate x pressure product at ischaemia was found in both those administered gallopamil (R 0.80, P less than 0.01) and diltiazem (R 0.65, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

New therapeutic strategies in the management of congestive heart failure

Congestive heart failure is a syndrome with multiple causes and manifestations. While rheumatic heart disease and hypertension are in decline, coronary artery disease is the leading cause in patients referred for evaluation of heart failure. Decrease in cardiac contractility and general neurohormonal activation, which trigger alterations in mechanical and biochemical factors in cardiac muscle and bring derangements of haemodynamics, are now considered as excessively early compensatory mechanisms which can be regarded as deleterious in patients with heart failure. Therapeutic principles illustrated in this article emphasize the importance of basic research and clinical observations derived from trials set the stage for therapeutic interventions. The approach to the patient with silent myocardial dysfunction must be treated so as to have the greatest beneficial impact on the prognosis of this disease.

Should we treat silent myocardial ischaemia?

Silent myocardial ischaemia has been documented in various clinical entities. Exercise testing and ambulatory ECG monitoring are the most widely used tests for documenting silent ischaemia, and both exercise-induced and daily life ischaemia have the potential to trigger prolonged functional and structural changes. Numerous clinical investigations in apparently healthy subjects, in stable and unstable angina, in patients with a previous myocardial infarction indicate that ischaemia has an adverse prognostic influence, independent of whether the ischaemia is silent or symptomatic. Methods for documenting silent ischaemia lead to different considerations according to each clinical syndrome of coronary artery disease. This review deals with the different intervention strategies derived from the unique prognostic profiles offered by silent ischaemia in a variety of clinical entities.

[The effects of pharmacological treatment in asymptomatic left ventricular dysfunction]

It is clearly settled that the management of overt heart failure offers poor prognostic impact due to the advanced setting of the disease. Relief of symptoms, objective benefits, as testified by short-term hemodynamic improvements, are as a matter of fact not reliable prognostic markers. Myocardial dysfunction starts early in the natural history of many cardiac diseases, and runs through the steps of progressive wall remodeling, witnessed by quantitative and qualitative changes in cells, interstitium and connective tissue. Experimental studies offered keys to interventions modulated to oppose the pathophysiological changes present in early myocardial dysfunction. At present, medical therapy has made great strides in testing early myocardial dysfunction. Angiotensin-converting enzyme inhibitors, which retard ventricular dilatation and thus may lower myocardial oxygen consumption requirements seem to offer a unique prognostic profile. Preliminary pilot studies on them and some of many large-scale multicentre trials still in progress reached evidence that this class of drugs is by this time a cornerstone of medical therapy, useful to lower cardiac events-rate in patients with heart failure.

Thrombolysis in refractory unstable angina

Multiple drug therapy, including nitrates, beta blockers, calcium antagonists, aspirin, and heparin, has been advocated as effective in the treatment of unstable angina, a syndrome with a multifactorial pathogenesis. Recently, plaque rupture and thrombosis have been demonstrated as the most important pathogenetic mechanisms. Nevertheless, clear-cut results on the effects of thrombolytic treatment in unstable angina are still lacking. Some possible explanations why the medical treatment of unstable angina has still not yet been standardized, whereas that of myocardial infarction has, are suggested. A review of randomized and nonrandomized studies published on this topic evaluating the role of different thrombolytic agents in unstable angina is presented. In addition the role of coronary angiography is discussed. In view of the disappointing results of coronary artery bypass surgery performed in the acute phase of the disease, one of the goals of clinical research is to identify subsets of patients at high and low risk and who undergo different types of therapeutic interventions. To support published data suggesting that total myocardial ischemia has a significant impact on prognosis, we present our results of a study carried out on patients with refractory unstable angina treated with thrombolytic therapy and evaluated with continuous electrocardiographic monitoring in the attempt to correlate total myocardial ischemia with short-term prognosis. Data in favor of the prognostic role of continuous electrocardiographic monitoring in unstable angina are also reviewed. Finally, we propose some suggestions that might be useful for future studies.

Thrombolytic therapy in refractory unstable angina: the role of Holter monitoring

We tested the safety and the usefulness of intravenous urokinase (2 million units administered over 30 min) in 44 patients with refractory unstable angina, defined as persistence of ischemic episodes during 48-h Holter monitoring (Phase 1) despite maximal medical therapy. After thrombolysis, recurrence of ischemia was observed during a week of observation in the CCU, including two 24-h Holter monitorings at the beginning and the end of the week (Phase 2). Seventeen patients completed the observation period without either symptomatic or asymptomatic ischemic episodes (Group A); the remaining 27 continued to manifest ischemia (Group B). No bleeding complications occurred. Within a 6-month follow-up, 2 patients of Group A had recurrence of unstable angina while in Group B, 19 patients had refractory angina or a major cardiac event [10 patients underwent coronary artery bypass surgery (CABG) or percutaneous transluminal coronary angioplasty (PTCA) for refractory angina (p less than 0.001), 6 other patients with refractory angina continued medical therapy, one patient had a myocardial infarction, and two patients died]. In Phase 1 the duration of total ischemia (min/24 h) was a relevant prognostic marker: higher duration correlated with adverse clinical outcome (p less than 0.01). In comparison to Phase 1, duration of total ischemia in Phase 2 was significantly reduced in both groups (16.9 +/- 19.6 vs. 25.4 +/- 17.7; p less than .001). A percent value expressing this variation was calculated for each patient: the variation thus obtained again gave information on the clinical outcome--the greater the reduction, the lower the risk of cardiac events (p less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Ergonovine maleate test detects anginal patients with poorly reproducible exercise tests

The aim of the study is to evaluate the reproducibility of exercise testing and to determine whether there is any correlation between the reproducibility of exercise test and response to the ergonovine maleate test. Thirty-eight patients with mixed angina and documented coronary artery disease underwent an ergonovine maleate test and four exercise tests on consecutive days in the same basal conditions. The ergonovine test was positive in 20 patients (Group I) and negative in 18 patients (Group II). There were no significant differences in the clinical and angiographic data of the two groups. All 152 exercise tests were positive. The variability of the response of the repeated tests was assessed by means of an analysis of the following parameters: heart rate, blood pressure, rate-pressure product, watts, and minutes were recorded at the onset of ischemia (ST decreases greater than or equal to 0.1 mV). Range (maximal-minimal obtained value), ratio between range and maximal obtained value, and coefficient of variation (standard deviation/mean of the four parameters) were calculated for each patient. The analysis of these values demonstrated that while the test was reproducible in some patients, a high individual variability was present in others. Moreover, the individual variability results were higher in Group I than in Group II, with a statistically significant difference for all considered parameters. In conclusion, it is possible to have a poorly reproducible exercise test in patients with mixed angina. The correlation between a positive ergonovine test and a poorly reproducible exercise test suggests that abnormal coronary vasomotion may sometimes be present during exercise and may affect the reproducibility of the test.

[Systemic fibrinolysis in patients with refractory unstable angina]

We tested the safety and the usefulness of intravenous fibrinolysis in 44 patients with refractory unstable angina, defined as persistence of ischemic episodes during 48-hour Holter monitoring (phase 1) despite maximal medical therapy. After fibrinolysis, recurrence of ischemia was recorded during 1 week of observation in CCU including 2 24-hour Holter monitoring at the beginning and at the end of this week (phase 2): 17 patients completed the observation period without either symptomatic or asymptomatic ischemic episodes (Group A); the remaining 27 patients continued to manifest ischemia (Group B). No bleeding complications occurred. Within a 6-month follow-up, 2 patients of Group A had recurrence of unstable angina while in Group B, 10 patients underwent CABG or PTCA for refractory angina, 6 other patients with refractory angina continued medical therapy, 1 patient had a myocardial infarction and 2 patients died (p less than 0.001). Phase 1: the duration of total ischemia (min/24 hours) was a relevant prognostic marker: higher duration correlated with adverse clinical outcome (p less than 0.01). Phase 2: in comparison with phase 1, duration of total ischemia was significantly reduced (p less than 0.001). A percent value expressing this variation was calculated for each patient: (min of ischemia in phase 2 - min of ischemia in phase 1/min of ischemia in phase 1). The variation thus obtained again gave information on the clinical outcome: the greater was the reduction, the lower was the risk of cardiac events (p less than 0.001). Our data suggest that: clinical stabilization may be obtained with the addition of fibrinolysis to conventional treatment; Holter monitoring bears prognostic information helpful in identifying patients who need further intervention.

Intravenous nifedipine prevents ergonovine-induced myocardial ischemia in patients with stable effort angina

Twelve of 40 consecutive patients with effort angina, documented coronary artery disease, and a positive exercise stress test had a positive ergonovine test. ST-segment depression (0.1 mV) occurred in ten and ST elevation (0.1 mV) in two patients. During the ergonovine maleate test the rate-pressure product recorded at the onset of ischemia (ST greater than or equal to 0.1 mV) was significantly lower than that recorded during the exercise stress test. The reproducibility of the rate-pressure product at ischemia was displayed in every patient with a second test; then, a third test after intravenous nifedipine infusion (1 mg over 5 minutes + 1 mg over 55 minutes) was performed. Six patients had negative results; out of the remaining six, three exhibited a significant increase in the dosage required for provoking ischemia. Both systolic and diastolic blood pressure were reduced by nifedipine, while only a slight increase in heart rate occurred, so that the rate-pressure product at any ergonovine dosage was decreased by nifedipine. No differences in the ischemic threshold during exercise and during the ergonovine maleate tests (in washout and after nifedipine) were found in patients with a positive or negative response to nifedipine. The ergonovine test was positive in a sizable (30%) number of patients with stable effort angina. In these patients nifedipine was effective in preventing ergonovine-induced myocardial ischemia.

Hypertension as a risk factor for sudden cardiac death and nonfatal myocardial infarction. Working Group of CNR Study OD1

To evaluate long-term prognosis during medical treatment of hypertension associated with angina pectoris, a total of 1083 patients with angiographically-documented coronary artery disease were followed for a mean of 66 months. At the end of the study, follow-up was complete in 98% of all patients. Of the 1083 patients, 132 (12%) had hypertension and 951 (88%) were not hypertensive. During the follow-up period, there was a total of 15 deaths (11.3%) among the hypertensive population (vs. 61 or 6.4% in the nonhypertensives) as well as a higher incidence of nonfatal myocardial infarction (9.0% in the hypertensives vs. 3.7% in the nonhypertensives) (Figure 2). Six-year cumulative survival was 84% in the hypertensive patients as compared to 92% in the nonhypertensives. Among risk factors, historical data, clinical and catheterization findings, the only noninvasively-obtainable independent predictor of prognosis using multivariate analysis was hypertension (Table 3).

Comparison of low-dose aspirin and coronary vasodilators in acute unstable angina

Episodic platelet activation has been shown to occur in unstable angina, and aspirin should have an important therapeutic role in the management of these patients. The response to aspirin alone or to aspirin in combination with vasodilators such as heparin and beta-blockers has been assessed in 41 patients with unstable angina. Therapy was added sequentially in the event of recurrence of transient myocardial ischemia. Patients were randomly assigned to two groups. Group 1 (21 patients) received an intravenous infusion of isosorbide dinitrate and oral diltiazem, and group 2 (20 patients) received intravenous aspirin (60 mg the first day and 20 mg on successive days). This dose of aspirin reduced serum thromboxane B2 from 160 +/- 88 ng/ml (mean +/- SD) to undetectable values (less than 6 ng/ml, p less than 0.01). If episodes of ischemic ST segment shift continued, the therapy of group 1 was added to that of group 2 or vice versa; if further ST segment changes were documented, intravenous heparin and oral beta-blockers were added; if episodes of myocardial ischemia persisted, urgent coronary arteriography and myocardial revascularization were performed. Nine patients in group 1 and six in group 2 (p = 0.8) had no further episodes of myocardial ischemia on their initial therapy; 12 additional patients had no further episodes when taking combined therapy of aspirin and vasodilators. Thus, the administration of aspirin alone was not superior to coronary dilators; 30% of all patients continued to have episodes of myocardial ischemia or had a myocardial infarction develop when heparin and beta-blockers were added. Myocardial infarction occurred in one patient on vasodilator therapy alone, in two on combined therapy, and in two on full therapy. These results suggest that in some patients, the stimulus to coronary thrombosis and vasoconstriction occasionally becomes so strong that it cannot be inhibited by certain antagonist drugs. The unstable tendency to continuation of ischemia or evolution to myocardial infarction is not related to the severity of the persisting stenosis. Those patients not promptly responding to combined therapy immediately from admission should have early coronary angiography and aggressive treatment.

Long-term survival in medically treated patients with ischaemic heart disease and prognostic importance of clinical and electrocardiographic data (the Italian CNR Multicentre Prospective Study OD1)

In order to study long-term survival in medically treated patients with ischaemic heart disease in our country and to evaluate the prognostic significance of clinical variables, 1083 patients less than 65 years old were followed up for a mean period of 66 months (min 36, max 93). All patients performed an exercise stress test and had coronary angiography. Vital status was known for 98.3% of the patients. The great majority were treated with calcium antagonists and nitrates. In the overall population, the annual cardiac mortality rate was 1.54%. On the basis of clinical variables, groups with a tenfold difference in mortality could be identified. The annual cardiac mortality was 0.29% in patients without myocardial infarction and effort ischaemia and reached 3.12% in those with extensive infarction and/or severe reduction of exercise tolerance. Among risk factors, only arterial hypertension was an independent predictor of mortality. According to angiographic variables, the highest mortality rate was 5.7% in patients with three-vessel disease and poor left ventricular function. When multivariate analysis was applied to clinically stratified subgroups, angiographic variables gave additional prognostic information on survival only in the subgroup with an intermediate prognosis. In conclusion (1) the annual cardiac mortality in our medically treated patients is low; (2) patients with very different prognoses may be identified on a clinical basis; (3) coronary angiography adds prognostic information only in moderately severe disease.

Clinical application of monitoring techniques: hemodynamic monitoring

In the diagnosis of myocardial ischemia continuous hemodynamic monitoring may contribute to detection of transient ischemia, to definition of location and to elimination of its pathogenesis, and to characterization of hemodynamic response to ischemia. It can be helpful in investigating the significance of negligible, non specific and/or short-lasting electrocardiographic changes accompanying typical anginal symptoms. Simultaneous right ventricular and left ventricular pressure monitoring gives information regarding biventricular interaction during episodes of transient ischemia: an early left ventricular dysfunction, with or without a late right ventricular impairment, a selective right dysfunction, and a simultaneous left ventricular and right ventricular impairment all represent the hemodynamic patterns associated with left, right and biventricular ischemia respectively. Monitoring of hemodynamic parameters related to myocardial oxygen consumption and the study of their changes preceding the onset of ischemia during both spontaneous and provoked episodes of ischemia, may help in identifying whether functional or organic factors or both are involved in the pathogenesis of transient ischemia in individual patients. Two principal hemodynamic patterns appear to be associated with transient ischemia: a) left ventricular and/or right ventricular impairment, usually beginning shortly before the onset of electrocardiographic changes, followed by a rapid recovery and often an overshooting, b) a sudden and sustained increase in systolic pressure and heart rate, simultaneous with the onset of ST-T changes. In both cases, the 'excitatory' pattern appears to be unrelated to pain.(ABSTRACT TRUNCATED AT 250 WORDS)

Impairment of myocardial perfusion and function during painless myocardial ischemia

Left ventricular (or pulmonary and systemic arterial) hemodynamics were measured for a mean of 13.6 hours during continuous electrocardiographic monitoring in 14 patients admitted to the coronary care unit because of angina at rest. Of 293 episodes of transient ST segment and T wave changes identified, 247 (84%) were completely asymptomatic. Sixty-three percent of asymptomatic episodes were associated with an elevation of the left ventricular end-diastolic or pulmonary artery diastolic pressure of 5 mm Hg or more; in 15% there were smaller elevations (2 to 4 mm Hg) and in 22% there were no changes or less than a 2 mm Hg elevation of pressure. The peak contraction and relaxation dP/dt (first derivative of left ventricular pressure) were reduced to 100 mm Hg/s or more in 84 and 81% of asymptomatic episodes, respectively. Great cardiac vein oxygen saturation measured in three patients showed an increased myocardial oxygen extraction similar to that seen in painful episodes, which preceded and accompanied asymptomatic electrocardiographic changes. These results indicate that asymptomatic electrocardiographic changes represent transient myocardial ischemia. Comparison of asymptomatic and symptomatic episodes revealed that asymptomatic episodes were generally shorter (253 +/- 159 versus 674 +/- 396 seconds, probability [p] less than 0.001) and produced less impairment of left ventricular function: there were smaller elevations of left ventricular end-diastolic or pulmonary artery diastolic pressure (5.9 +/- 5.0 versus 16.5 +/- 6.9 mm Hg, p less than 0.001), and smaller reductions of peak left ventricular contraction dP/dt (252 +/- 156 versus 395 +/- 199 mm Hg/s, p less than 0.001) and relaxation dP/dt (259 +/- 191 versus 413 +/- 209 mm Hg/s, p less than 0.001). In individual patients, however, asymptomatic and symptomatic episodes of similar duration and severity were observed. The duration and severity of ischemia appear important for the genesis of anginal pain, but additional factors must be involved.

[The role of spasm in angina pectoris, myocardial infarction and sudden death. Indications for future research and treatment]

Recent concepts on the role of coronary artery spasm and other forms of vasoconstriction in coronary artery disease are studied with particular reference to episodes of transient ischemia and their therapeutic implications. The possible contribution of spasm and other obstructive mechanisms such as platelet agregation, to the different forms of angina, myocardial infarction and sudden death, is analysed in the light of clinical observations, some of which have not previously been reported. Based on these concepts and clinical considerations, new orientations for future research and treatment are suggested. In our series, long term treatment of coronary artery disease with the association of nitrate derivatives are suggested. In our series, long term treatment of coronary artery disease with the association of nitrate derivatives and calcium antagonists has led to a reduction in mortality and in the incidence of myocardial infarction over periods ranging from 2 to 4 years.

Increased fibrinopeptide A formation and thromboxane A2 production in patients with ischemic heart disease: relationships to coronary pathoanatomy, risk factors, and clinical manifestations

In 98 patients with ischemic heart disease (IHD), independent of their clinical status (previous myocardial infarction, spontaneous angina or effort angina), a hypercoagulable state (indicated by significant elevation of fibrinopeptide A plasma level) and an increased platelet biologic activity were observed. Moreover, plasma fibrinopeptide A concentration and platelet aggregation were remarkably higher in patients with frequently occurring spontaneous clinical manifestations (active disease) than in IHD patients with relatively quiescent symptoms. Abnormalities of blood clotting and platelet changes were not significantly altered by the presence of severity of coronary angiographic fixed obstruction in IHD. Multiple regression analysis indicated that hypercoagulability and increased platelet biologic activity were not a consequence of differences in risk factor patterns in IHD patients compared to control subjects.

Sequence of events in angina at rest: primary reduction in coronary flow

To investigate the events that lead to acute myocardial ischemia we monitored continuously the ECG, the left ventricular (four patients) or aortic (two patients) pressure and the great cardiac vein oxygen saturation (CSO2S) by a fiberoptic catheter in six patients with frequent anginal attacks at rest. We recorded 137 transient ischemic episodes (10 with chest pain) characterized by ST-segment elevation in 28 episodes, depression in three episodes and by pseudonormalization of previously inverted or flat T waves in 106 episodes. The onset of electrocardiographic and hemodynamic changes was preceded by a large drop in CSO2S in all 135 episodes with ST-T changes in the anterior leads but not in two episodes with ST elevation on inferior leads. The fall in CSO2S, consistently followed by signs of left ventricular function impairment and never preceded by any detectable increase in the hemodynamic determinants of myocardial oxygen consumption, probably reflects a reduction in regional perfusion. Thus, a reduction in coronary flow may cause transient ischemia in patients with angina at rest. These episodes may be associated with variable, often minor electrocardiographic changes and occasionally with anginal pain.