Circulating cardiovascular biomarkers in recurrent atrial fibrillation: data from the GISSI-atrial fibrillation trial

OBJECTIVE

we evaluated the prognostic role of circulating cardiovascular biomarkers in patients with a history of recent atrial fibrillation (AF).

BACKGROUND

predicting long-term maintenance of sinus rhythm in patients with AF is difficult.

METHODS

plasma concentrations of three specific cardiac markers [high-sensitivity troponin T (hsTnT), N-terminal probrain natriuretic peptide (NT-proBNP) and mid-regional proatrial natriuretic peptide (MR-proANP)] and three stable fragments of vasoactive peptides [mid-regional proadrenomedullin (MR-proADM), copeptin (CT-proAVP) and CT-proendothelin-1 (CT-proET-1)] were measured at baseline and after 6 and 12 months in 382 patients enrolled in the GISSI-AF study, a prospective randomized trial to determine the effect of valsartan to reduce the recurrence of AF. The association between these markers, clinical characteristics and recurrence of AF was tested by univariate and multivariate Cox models.

RESULTS

mean patient age was 68 ± 9 years (37.2% females). A total of 84.8% of patients had a history of hypertension. In total, 59.7% qualified for history of AF because of successful cardioversion, 11.8% because of two or more episodes of AF in the 6 months preceding randomization and 28.5% because of both. Patients in AF at 6 or 12 months (203 (53.1%) with first recurrence) had significantly higher concentrations of most biomarkers. Despite low baseline levels, higher concentrations of hsTnT {adjusted hazard ratio (HR) [95% confidence intervals (CIs) for 1 SD increment] (1.15 [1.04-1.28], P = 0.007), MR-proANP (1.15 [1.01-1.30], P = 0.04), NT-proBNP (1.24 [1.11-1.39], P = 0.0001) and CT-proET-1 (1.16 [1.01-1.33], P = 0.03) independently predicted higher risk of a first recurrence of AF. Changes over time of MR-proANP tended to predict subsequent recurrence (adjusted HR [95%CI]) (1.53 [0.98-2.37], P = 0.06).

CONCLUSION

circulating markers of cardiomyocyte injury/strain and endothelin are related to recurrence of AF in patients in sinus rhythm with a history of recent AF.

Multislice CT in emergency room management of patients with chest pain and medium-low probability of acute coronary syndrome

PURPOSE

The main cause of acute chest pain, which accounts for 6.5% of urgent medical examinations in emergency rooms in Italy, is acute coronary syndrome (ACS). We performed this prospective study to evaluate the diagnostic accuracy of a 16-channel computed tomography (CT) scanner with dedicated software in a group of patients with chest pain and medium to low risk of ACS.

MATERIALS AND METHODS

This study involved a selected group of 31 patients reporting chest pain with a medium to low probability of ACS, defined on the basis of preliminary tests [electrocardiogram (ECG) and serum cardiac markers]. Coronary angiography, performed within 24 h of MSCT, was used as the gold standard.

RESULTS

MSCT identified the presence of occlusions and significant (>50%) or nonsignificant stenoses in the main coronary segments, with a sensitivity of 65%, a specificity of 98.8%, a positive predictive value (PPV) of 81.2%, a negative predictive value (NPV) of 97.3% and an accuracy of 96.4%. Significant stenoses and occlusions were detected with a sensitivity of 71.4%, a specificity of 99.6%, a PPV of 93.7%, an NPV of 97.7% and an accuracy of 97.5%.

CONCLUSIONS

Due to its high NPV, this technique can rule out significant stenoses or coronary occlusions provided that image quality is excellent. In patients with a medium to low coronary risk, MSCT is a more accurate indicator of the need for coronary angiography than is exercise stress testing, which is less expensive but has lower predictive values.

Pre-discharge stress echocardiography and exercise ECG for risk stratification after uncomplicated acute myocardial infarction: results of the COSTAMI-II (cost of strategies after myocardial infarction) trial

OBJECTIVE

To compare in a prospective, randomised, multicentre trial the relative merits of pre-discharge exercise ECG and early pharmacological stress echocardiography concerning risk stratification and costs of treating patients with uncomplicated acute myocardial infarction.

DESIGN

262 patients from six participating centres with a recent uncomplicated myocardial infarction were randomly assigned to early (day 3-5) pharmacological stress echocardiography (n = 132) or conventional pre-discharge (day 7-9) maximum symptom limited exercise ECG (n = 130).

RESULTS

No complication occurred during either stress echocardiography or exercise ECG. At one year follow up there were 26 events (1 death, 5 non-fatal reinfarctions, 20 patients with unstable angina requiring hospitalisation) in patients randomly assigned to early stress echocardiography and 18 events (2 reinfarctions, 16 unstable angina requiring hospitalisation) in the group randomly assigned to exercise ECG (not significant). The negative predictive value was 92% for stress echocardiography and 88% for exercise ECG (not significant). Total costs of the two strategies were similar (not significant).

CONCLUSION

Early pharmacological stress echocardiography and conventional pre-discharge symptom limited exercise ECG have similar clinical outcome and costs after uncomplicated infarction. Early pharmacological stress echocardiography should be considered a valid alternative even for patients with interpretable baseline ECG who can exercise.

Exercise-electrocardiography and/or pharmacological stress echocardiography for non-invasive risk stratification early after uncomplicated myocardial infarction. A prospective international large scale multicentre study

AIMS

The aim of the present study was to assess the relative prognostic value of clinical variables, the exercise electrocardiography test and the pharmacological stress echocardiography test either with dipyridamole or dobutamine early after a first uncomplicated acute myocardial infarction in a large, multicentre, prospective study.

METHODS AND RESULTS

Seven hundred and fifty-nine in-hospital patients (age=56+/-10 years) with a recent and first clinical uncomplicated myocardial infarction, with baseline echocardiographic findings of satisfactory quality, an interpretable ECG and able to exercise underwent a resting 2D echocardiogram, a pharmacological stress test with either dipyridamole or dobutamine and an exercise electrocardiography test at a mean of 10 days from the infarction; they were followed-up for a median of 10 months. During the follow-up, there were 13 deaths, 23 non-fatal myocardial infarctions and 59 re-hospitalizations for unstable angina. When all spontaneous events were considered, with multivariate analysis, the difference between the wall motion score index at rest and peak stress (delta wall motion score index), and exercise duration were independent predictors of future spontaneous events (relative risk 7.2; 95% CI=2.73-19.1; P=0.000; relative risk 1.1, 95% CI=1.02-1.18; P=0.008, respectively). Kaplan-Meier survival estimates showed a better outcome for those patients with a negative pharmacological stress echocardiography test compared to patients with low dose positivity (94.7 vs 74.8%, P=0.000).

CONCLUSION

Stress echocardiography tests provide stronger information than historical and exercise electrocardiography test variables. Pharmacological echocardiography as well as the exercise ECG is able to predict all spontaneously occurring events when the presence as well as the timing, severity, and extension of stress-induced wall motion abnormalities are considered.

Safety, feasibility, and diagnostic accuracy of accelerated high-dose dipyridamole stress echocardiography

Protocols for dipyridamole stress testing have evolved in the last 16 years in the neverending quest of optimal diagnostic accuracy and user friendliness. Higher dipyridamole dose in a shorter infusion time provides higher sensitivity, but concern over safety is still controversial. An accelerated high-dose (0.84 mg/kg in 6 minutes without atropine) dipyridamole stress test was performed on 1,295 patients in 2 echocardiographic laborotories: Institute of Clinical Physiology of Pisa and Niguarda Hospital of Milan. During testing, there were no deaths and no patients had ventricular fibrillation. Major adverse reactions occurred in 3 cases (1 every 431 studies): 1 myocardial infarction, 1 brief cardiac asystole, and 1 transient ischemic attack. Overall feasibility was 97%. In 66 patients with normal function at rest who were evaluated off therapy, with coronary angiography performed independently of test results, the accelerated high-dose protocol showed a sensitivity of 85% (confidence interval [CI] 73% to 92%) and a specificity of 93% (CI 83% to 97%) for angiographically assessed coronary artery disease (quantitatively assessed diameter reduction > or = 50%). Diagnostic accuracy of the accelerated high dose was 89% (CI 79% to 95%). Thus, accelerated high-dose dipyridamole stress echocardiography was reasonably safe and well tolerated. This protocol is especially appealing for its excellent diagnostic accuracy coupled with the short imaging time and no need for drug cocktails.

Stent implantation without predilation in patients with a single, noncalcified coronary artery lesion

The purpose of this study was to assess the feasibility of stent implantation without predilation in patients with a single, noncalcified coronary artery lesion. A total of 122 patients were randomized to receive a stent with or without predilation; direct stent placement was possible in 59 of the 61 patients (97%) with an immediate and long-term clinical follow-up similar to that observed in the group of patients treated conventionally.

High dose dipyridamole myocardial imaging: simultaneous sestamibi scintigraphy and two-dimensional echocardiography in the detection and evaluation of coronary artery disease. Italian Group of Nuclear Cardiology

BACKGROUND

Dipyridamole stress combined with echocardiography or perfusion scintigraphy can be used to detect coronary artery disease, but head-to-head comparative data are lacking. The aim of this study was to compare the relative accuracy of high-dose dipyridamole stress imaging (up to 0.84 mg/kg over 10 min) with two-dimensional echocardiography and sestamibi perfusion scintigraphy in detecting coronary artery disease.

METHODS

One-hundred and one patients with a history of chest pain and no previous myocardial infarction, were studied simultaneously using planar perfusion scintigraphy and echocardiography during a high-dose dipyridamole stress, at seven different institutions.

RESULTS

During coronary angiography, 21 patients had non-significant lesions, and 80 had significant lesions (> or = 50% diameter reduction): 37 had single-, 19 double- and 24 triple-vessel disease. Sensitivity for disease detection was 78% [95% confidence interval (CI) 67-86%] for echocardiography and 79% (CI 68-87%) for scintigraphy. The specificity was 76% (CI 67-84%) for echocardiography and 90% (CI 83-95%) for scintigraphy. The inter-center variation in accuracy ranged from 50 to 100% for echocardiography (coefficient of variation 19.7%) and from 71 to 100% for scintigraphy (coefficient of variation 15%). The angiographically assessed extent and severity of coronary artery disease, evaluated using the Duke score, was correlated to the extent and severity of perfusion defects with scintigraphy (r = 0.65, P < 0.0001) and regional wall motion abnormalities by echocardiography (r = 0.57, P < 0.0001).

CONCLUSIONS

Perfusion scintigraphy and echocardiography have similar accuracies for the non-invasive identification of angiographically assessed coronary artery disease during high-dose dipyridamole stress. Inter-center variability in diagnostic accuracy is higher for echocardiography than scintigraphy. Both methods allow a reasonably accurate estimation of extent and severity of disease, via a semiquantitative assessment of extent and severity of perfusion of functional defects.

Value of pharmacologic stress echocardiography in risk stratification of patients with single-vessel disease: a report from the Echo-Persantine and Echo-Dobutamine International Cooperative Studies

OBJECTIVES

This study sought to verify the effectiveness of pharmacologic stress echocardiography in risk stratification of patients with single-vessel disease.

BACKGROUND

Noninvasive prognostic assessment of single-vessel disease is an unresolved issue to date.

METHODS

The study evaluated prospectively collected data from 754 patients with angiographic single-vessel disease who underwent either dipyridamole (n = 576) or dobutamine (n = 178) stress echocardiography. Invasive treatment (coronary revascularization within 3 months of stress testing) was performed in 260 patients and medical treatment in 494.

RESULTS

Echocardiographic positivity was observed in 421 patients (56%). Patients treated invasively had a higher incidence of stress test positivity (69% vs. 49%, p < 0.001) and left anterior descending coronary artery involvement (60% vs. 46%, p < 0.001) than patients maintained with medical therapy. During a mean follow-up of 37 months, 54 hard cardiac events occurred (14 deaths, 40 nonfatal infarctions): 37 in medically and 17 in invasively treated patients (7.5% vs. 6.5%, p = NS). On Cox analysis, a positive result on stress testing was the only independent prognostic predictor in medically treated patients (relative risk 2.92, 95% confidence interval 1.29 to 6.59). The 4-year infarction-free survival rate was higher for a negative than a positive stress test result in medically (93.9% vs. 87.3%, p = 0.009) but not invasively treated patients (92.7% vs. 97.1%, p = 0.545). Moreover, a significantly higher 4-year infarction-free survival rate was found in invasively versus medically treated patients with a positive (p = 0.012), but not in those with a negative, stress test result (p = 0.853).

CONCLUSIONS

Pharmacologic stress echocardiography is effective in risk stratification of single-vessel disease and can accurately discriminate patients in whom coronary revascularization can have the maximal beneficial effect. These findings have a potential favorable impact on the cost-effectiveness of invasive procedures.

Which variable of stenosis severity best describes the significance of an isolated left anterior descending coronary artery lesion? Correlation between quantitative coronary angiography, intracoronary Doppler measurements and high dose dipyridamole echocardiography

OBJECTIVES

This study sought to investigate the angiographic or intracoronary Doppler variables of stenosis severity that best correlate with the results of dipyridamole echocardiography.

BACKGROUND

Quantitative coronary angiography and intracoronary Doppler flow velocity assessments are the commonly used techniques for the objective identification of significant coronary artery stenosis.

METHODS

Thirty patients with an isolated lesion of the left anterior descending coronary artery (LAD) were studied by means of on-line quantitative coronary arteriography, intracoronary Doppler flow velocity measurements and dipyridamole echocardiography 6 months after percutaneous transluminal coronary angioplasty. The quantitative arteriographic analyses were performed on-line; post-stenotic Doppler flow velocities were measured at baseline and after adenosine infusion. Angiographic and Doppler measurements were compared with the corresponding dipyridamole echocardiographic data and analyzed by discriminant analysis.

RESULTS

The dipyridamole echocardiographic response was positive in 11 patients (37%). The best cutoff values for predicting an abnormal echocardiographic response were 1) stenotic flow reserve of 2.8 (p = 0.0001); 2) 59% diameter stenosis (p = 0.0001); 3) minimal lumen diameter of 1.35 mm (p = 0.001); 4) coronary flow reserve of 2.0 (p = 0.0002); and 5) maximal peak velocity of 60 cm/s during hyperemia (p = 0.04). Multivariate analysis identified stenotic flow reserve as the only independent predictor of ischemia during dipyridamole echocardiography.

CONCLUSIONS

Stenotic flow reserve is the variable that best describes the functional significance of an isolated LAD lesion, and a value of 2.8 is the best predictor of a positive dipyridamole echocardiographic response. Furthermore, angiographic variables of stenosis severity relate to echocardiographic test results better than intracoronary Doppler variables.

Dipyridamole thallium-201 imaging very early after uncomplicated acute myocardial infarction in patients treated with thrombolytic therapy

The aim of this study was to assess the safety and prognostic value of dipyridamole 201T1 imaging very early after acute myocardial infarction in patients treated with thrombolytic therapy. Fifty-two consecutive patients with an uncomplicated clinical course underwent quantitative planar dipyridamole 201T1 imaging 2 5 days after acute myocardial infarction. The patients were followed for 14 +/- 7 months after discharge. No major complications occurred during the test. Of the 30 patients with redistribution, five (16.6%) developed in-hospital unstable angina as against none of the 22 patients without redistribution. During follow-up, a total of live late cardiac events were observed: two deaths and two cases of unstable angina in the group with reversible defects and one reinfarction in the group with fixed defects. The 1-year actuarial probability of being free of cardiac events was, respectively, 66 +/- 10% and 94 +/- 5% in the patients with and without redistribution (P < 0.01). In conclusion, in patients treated with thrombolysis, dipyridamole-201T1 imaging very early after uncomplicated acute myocardial infarction is a feasible and safe test. Patients with fixed defects appear to be at low risk and may be candidates for early discharge; the presence of redistribution identifies a subgroup of patients who may benefit from further careful clinical evaluation.

The relative value of exercise-electrocardiography and dipyridamole stress echocardiography for risk stratification early after uncomplicated myocardial infarction. The EPIC (Echo Persantine International Cooperative) Study Group

BACKGROUND

Rational prognostic algorithm should be developed considering the logical progression of the information as it becomes available to the physician, with clinical data first, ECG data second and stress imaging data last. The aim of the present study was to assess in a clinically realistic fashion the relative prognostic value of exercise electrocardiography test (EET) and dipyridamole-echocardiography test (DET) early after first acute uncomplicated myocardial infarction.

METHODS AND RESULTS

Five hundred and forty-seven in-hospital patients (age = 56 +/- 9 years) with recent clinically uncomplicated first myocardial infarction, baseline echocardiographic findings of satisfactory quality, interpretable ECG and capability to exercise underwent a resting 2D echocardiogram, a DET and an EET at a mean of 10 days from the infarction and were followed up for 16.2 +/- 11 months. During the follow-up, there were 17 cardiac deaths, 19 non-fatal myocardial infarctions and 49 unstable angina. When cardiac death was considered as the only significant event, with multivariate analysis, peak dipyridamole Wall Motion Score Index was the only significant predictor (chi 2 = 5.66; p = 0.013; relative risk estimate = 4.7; confidence intervals = 1.35-16.08). In presence of a negative exercise electrocardiography test for both chest pain and electrocardiographic criteria, the death rate was 2%.

CONCLUSION

DET provides stronger information in comparison with historical and EET variables. However, a negative maximal EET is sufficient to identify a very low risk subset in whom additional testing may not be warranted.

Coronary angiography and aorto-coronary bypass surgery in type 2 diabetic patients

Diabetic and non-diabetic subjects with angina who underwent angiography and were subsequently treated surgically or medically and followed up for 5 years were analysed in order to assess coronary angiographic findings, efficacy of coronary artery bypass grafting and prognostic criteria in Type 2 diabetic patients with angina as compared to non-diabetic subjects. A total of 1853 of non-diabetic and 145 diabetic subjects underwent angiography, including respectively 857 and 68 who had surgery. Perioperative mortality, survival, reinfarction and asymptomaticity rates were measured. Multivariate analysis of risk factors and clinical features was performed. Diabetic patients had a higher frequency of multi-vessel stenoses (p < 0.001), a greater diffusion of stenoses (p < 0.005) and worse left ventricular motion (p < 0.005). No differences were found in perioperative infarction and mortality. Operated diabetic patients had a higher survival rate (p < 0.001) and a longer symptom-free period (p < 0.05) than unoperated diabetic patients. Operated diabetic patients had similar survival and more frequent recurrence of angina (p < 0.05) than operated non-diabetic patients. Survival rate was lower for unoperated diabetic patients than unoperated non-diabetic patients (p < 0.05). Recurrence of angina was similar. Multivariate analysis did not indicate diabetes as a factor affecting survival. It is concluded that surgery for Type 2 diabetic patients with coronary artery disease is a suitable therapeutic option conferring a reduction in mortality regardless of the presence of diabetes.

Value of transthoracic two-dimensional echocardiography in predicting viability in patients with healed Q-wave anterior wall myocardial infarction

The role of transthoracic echocardiography as a predictor of recovery after revascularization has not yet been established. Two-dimensional echocardiography was performed in 15 patients with a healed anterior wall myocardial infarction and severe, isolated stenosis of the left anterior descending coronary artery before, and 3 to 6 months after angiographically confirmed successful revascularization. The asynergic segments were classified into 2 groups according to 2 different echocardiographic patterns: those showing a normal acoustic reflectance with normal end-diastolic thickness (pattern A segments) and those showing an increase in acoustic reflectance and reduced end-diastolic thickness (pattern B segments). We hypothesized that pattern A segments were more likely to recover (viable myocardium) and that pattern B segments were consistent with irreversibility. A total of 240 segments in the 15 patients were evaluated before and after revascularization. Sixty-seven segments were asynergic; of these, 52 were judged to have pattern A and 15 pattern B. Of the 52 pattern A segments, 27 were hypokinetic and 25 akinetic. All of the pattern B segments were akinetic (n = 9) or dyskinetic (n = 6). Pattern A was predictive of postoperative recovery in 39 of 52 segments (75%) (p < 0.0001); pattern B was predictive of irreversibly damaged tissue in 13 of 15 segments (87%) (p < 0.0001). Thus, in patients with healed anterior wall myocardial infarction, resting transthoracic echocardiography is a simple and reliable predictor of the behavior of asynergic segments after revascularization.

Strategy of diagnostic imaging before and after PTCA

It is now widely accepted that percutaneous transluminal coronary angioplasty (PTCA) is an effective nonsurgical technique for achieving coronary revascularization. Exercise electrocardiography remains the standard procedure for functional evaluation before, early, and late after angioplasty because of its availability, safety, and limited cost. The drawback of exercise testing is its low specificity and the fact that the attainment of diagnostically useful data requires a level of exercise that substantially increases myocardial oxygen demand. Exercise thallium imaging has been shown to be highly predictive of restenosis and adverse events after angioplasty, but it is possible that myocardial perfusion may not return to normal immediately after successful revascularization. Stress echocardiography has many practical advantages over scanning tests, as result of its lower cost, shorter imaging time, and the absence of radiation exposure. Dipyridamole echocardiography testing (DET) is an exercise-independent method of evaluating patients who have to undergo coronary angioplasty. Before PTCA, DET allows the clinician to localize the site and extent of myocardial ischemia anatomically. Early after a successful procedure, DET identifies a group at high risk for the late recurrence of symptoms. Late after PTCA, DET is more accurate than exercise electrocardiography in detecting restenosis or disease progression. In asymptomatic patients with exercise-induced ST depression, DET has the same good diagnostic accuracy as thallium scintigraphy. For these reasons, as well as because of its noninvasive nature and availability, DET should be considered an attractive option for the evaluation of patients after anatomically successful angioplasty.

Maldistribution of regional myocardial perfusion at rest in patients with coronary artery disease and no previous myocardial infarction, evidenced by 99mTc-Sestamibi scintigraphy

Since myocardial 99mTc-Sestamibi uptake is closely related to coronary blood flow and the tracer does not redistribute, resting perfusion defects may be observed even in viable regions supplied by vessels with severe stenosis. The incidence and the clinical significance of 99mTc-Sestamibi uptake defects at rest were investigated in 60 men with suspected coronary artery disease and no previous myocardial infarction, in a multicenter study. Of 60 patients, 12 showed normal coronary arteries and 48 significant coronary artery disease (> 50% luminal narrowing). Based on the presence or absence of tracer uptake defects at resting planar scans, the patients were divided into Group 1 (27 patients) and Group 2 (33 patients), respectively. A greater incidence of coronary artery disease (100% versus 64%, p < 0.01) and of multivessel disease (70% versus 36%, p < 0.05) was observed in patients of Group 1. All patients underwent dipyridamole (up to 0.84 mg/kg in 10 min) 99mTc-Sestamibi scintigraphy, which more frequently induced transient 99mTc-Sestamibi uptake defects in Group 1 than in Group 2 (85% versus 42%, p < 0.001). A high incidence of resting 99mTc-Sestamibi uptake defects was observed in patients without previous myocardial infarction; this identified a subset of patients with a higher prevalence of coronary artery disease and multivessel involvement and with a greater impairment of the coronary reserve, as evidenced by a dipyridamole test.

Exercise thallium scintigraphy versus high-dose dipyridamole echocardiography testing for detection of asymptomatic restenosis in patients with positive exercise tests after coronary angioplasty

The usefulness of high-dose (< or = 0.84 mg/kg over 10 minutes) dipyridamole echocardiography testing was compared with that of exercise thallium-201 scintigraphy in detecting restenosis (> 70% lumen reduction) in 50 asymptomatic patients with ST-segment depression during maximal exercise testing 3 months after successful coronary angioplasty. Dipyridamole echocardiography testing and exercise thallium scintigraphy showed a similar sensitivity (75 vs 83%; p = NS) and specificity (90 vs 84%; p = NS) for the detection of restenoses, which occurred in 12 patients. It is concluded that dipyridamole echocardiography testing is as accurate as exercise thallium testing for the noninvasive detection of severe restenosis in patients with exercise-induced asymptomatic ST-segment depression after successful angioplasty. Furthermore, the site, extent and severity of the thallium perfusion defects during exercise are correlated to those of the dyssynergy during dipyridamole echocardiography.

Residual coronary reserve despite decreased resting blood flow in patients with critical coronary lesions. A study by technetium-99m human albumin microsphere myocardial scintigraphy

BACKGROUND

Experimental data demonstrate the persistence of a transmural vasodilator reserve in the face of depressed resting myocardial perfusion. The present study was designed to determine whether resting myocardial hypoperfusion indicates exhausted coronary reserve (CR).

METHODS AND RESULTS

Fifteen patients with stable angina, isolated left anterior descending coronary artery (LAD) stenosis, and no previous myocardial infarction were evaluated by means of 99mTc human albumin microsphere scintigraphy. Regional myocardial perfusion and CR were assessed at baseline and after LAD papaverine (10-12 mg) by means of two microsphere injections in the left ventricle and compared with five normal subjects. Two 300-second scans were obtained with a mobile gamma camera positioned in the 70 degrees left anterior oblique projection; actual microsphere distribution after papaverine was obtained by image subtraction. The two arterial input functions (basal and papaverine) were measured from the first-pass time-activity curves and validated with the reference arterial sample technique. From the comparison of circumferential profile analysis between patients and normal subjects, nine patients (group 1A) showed perfusion defects at rest (reduction of percent radioactivity below 2 SD of normal subjects) in the LAD territory, and the other six (group 1B) showed homogeneous perfusion. CR (papaverine/resting perfusion) was 3.8 +/- 0.2 and 1.51 +/- 0.27 in normal subjects and in ischemic patients, respectively (p < 0.01). Despite resting hypoperfusion, group 1A showed a papaverine-recruitable CR similar to that of group 1B (1.57 +/- 0.33 and 1.43 +/- 0.16, respectively, p = NS).

CONCLUSIONS

In patients with stable angina pectoris, isolated LAD stenosis, and no previous myocardial infarction, microsphere scintigraphy disclosed a high incidence of resting perfusion defects; in those patients, a residual CR was observed despite decreased resting blood flow.

High-dose dipyridamole echocardiography test in coronary artery disease after heart transplantation

In order to evaluate the usefulness of the high-dose dipyridamole echocardiography test (DET) for the detection of coronary artery disease (CAD) after heart transplant and for the assessment of prognosis, 80 heart transplant patients underwent this test within 48 h of the scheduled yearly coronary angiography. Coronary angiography showed normal coronary arteries in 55 patients and CAD in 25, eight of whom had > 50% luminal narrowing. Segmental hypokinesis on baseline echocardiography was present in 27 patients, 19 of whom had CAD (sensitivity = 76%; specificity = 85%). DET was negative in all the patients with normal coronary arteries (specificity = 100%). Out of 25 patients with CAD, eight had a positive DET and 17 a negative DET (sensitivity 32%), but DET was positive in seven of the eight patients with coronary artery stenosis > 50% (sensitivity 87%). During follow-up (9.8 +/- 4.5 months) seven cardiac events occurred in seven patients, all with CAD and wall motion hypokinesis (six on baseline echocardiogram and four after dipyridamole infusion). In our experience, DET does not seem adequate for the screening of post-transplant CAD, but useful in identifying patients with severe lesions (> 50%). Wall motion abnormalities on baseline echocardiogram or after dipyridamole infusion might identify patients who require closer surveillance. A longer experience is needed to confirm these results.

[The PTCA of venous grafts: the immediate and long-term results]

BACKGROUND AND METHODS

From June 1981 to September 1991, 30 coronary angioplasty procedures were performed in 25 patients with lesions of saphenous vein grafts. The mean time between bypass surgery and PTCA was 63.1 months (range: 2-168 months). The clinical indications for PTCA were: stable angina in 25 cases; unstable angina in 2 and silent ischemia in 3. The treated lesions were localized at the proximal anastomosis site in 12 cases, in the midshaft in 11 and at the distal anastomosis in 10.

IMMEDIATE RESULTS

Twenty-five procedures (83.3%) were successful with a mean residual stenosis of 24% +/- 9%; 1 procedure was unsuccessful and 4 were complicated (13.3%) (1 death in the catheterization laboratory; 1 non Q wave acute myocardial infarction, and 2 emergency bypass operations). The only factor predicting the immediate result was the stenosis morphology (p < 0.05). LONG-TERM CLINICAL FOLLOW-UP. The 20 patients with a first successful PTCA were followed up clinically for a mean period of 36.3 months (range: 1-120 months). There were no deaths nor acute myocardial infarctions. Ten patients (50%) remained completely asymptomatic for the follow-up period. Ten subjects (50%) had recurrence of angina, treated medically in 4 (20%) and with a repeat PTCA in 6 (30%) (for restenosis in 5 cases and for disease progression in 1). Three (15%) of these patients with a repeat PTCA had a new recurrence and were sent to surgery. Sixty-five percent of the patients where asymptomatic at the last clinical control after one or repeat PTCA. We did not find any statistically significant predictor of events (angina) at follow-up.

CONCLUSIONS

In our experience PTCA for lesions of saphenous vein grafts is a feasible procedure with acceptable initial success and a favourable long-term outcome.

Safety of intravenous high-dose dipyridamole echocardiography. The Echo-Persantine International Cooperative Study Group

Clinical data on 10,451 high-dose (up to 0.84 mg/kg over 10 minutes) dipyridamole-echocardiography tests (DET) performed in 9,122 patients were prospectively collected from 33 echocardiographic laboratories, each contributing greater than 100 tests. All patients were studied for documented or suspected coronary artery disease (1,117 early [less than 18 days] after acute myocardial infarction and 293 had unstable angina). Significant side effects including major adverse reactions and minor but limiting side effects occurred in 113 patients (1.2%). Major adverse reactions occurred in 7 cases (0.07%). In 6 of these cases, adverse reactions were associated with echocardiographically assessed ischemia and included 1 prolonged cardiac asystole (complicated by acute myocardial infarction and coma, with death after 23 days), 1 short-lasting cardiac asystole, 2 myocardial infarctions, 1 pulmonary edema and 1 sustained ventricular tachycardia. In all 6 cases, the cardiologist-echocardiographer performing the study had a limited experience (less than 100 tests) with DET, and at off-line reading in 5 cases, the obvious echo-positivity preceded the onset of complications by 1 to 5 minutes. The only ischemia-independent major side effect was a short-lasting cardiac asystole that was reversed by aminophylline and atropine. Significant side effects associated with echocardiographically assessed ischemia occurred in 89 additional cases (21 with and 68 without concomitant echocardiographically assessed myocardial ischemia). The most frequent of these side effects was hypotension or bradycardia, or both, which occurred in 40 patients with negative and 6 with positive DET. In all cases, side effects promptly subsided after aminophylline. In 1,857 cases, the high dose was not given for echo-positivity before the eighth minute.(ABSTRACT TRUNCATED AT 250 WORDS)

Value of negative predischarge exercise testing in identifying patients at low risk after acute myocardial infarction treated by systemic thrombolysis

Although thrombolytic therapy reduces mortality in patients with acute myocardial infarction (AMI), it is associated with a greater incidence of successive coronary events, and there is still no ideal diagnostic and therapeutic strategy for such patients. The present study verifies the value of negative predischarge exercise testing in identifying low-risk patients treated with thrombolysis after AMI. One hundred fifty-seven consecutive patients with an uncomplicated clinical course underwent maximal or symptom-limited exercise testing (Bruce treadmill protocol) within 15 days of AMI in the absence of therapy. The location of the AMI was anterior in 51 patients, inferior in 85 and non-Q-wave in 21. All of the patients were followed for 6 months. Death and nonfatal reinfarction were considered as major coronary events, and the recurrence of angina as a minor event. Exercise test results were negative in 105 patients (group 1) and positive for angina or ST depression greater than or equal to 0.1 mV in 52 (group 2). No deaths occurred during follow-up; there were 3 reinfarctions (3%) and 7 cases (7%) of postinfarction angina in group 1, and 2 reinfarctions (4%) and 21 cases (40%) of postinfarction angina in group 2. By the end of follow-up, 90% of the patients with negative exercise test results were event-free (97% in the case of major events). These results show that thrombolytic therapy does not affect the value of negative postinfarction exercise testing in identifying low-risk patients.

Thallium-201: what do we gain from new clinical protocols and acquisition procedures? The Italian Study on Thallium Reinjection/SIRT)

Nine medical centers, equipped with the same gamma camera and computer software, participated in this multicenter study on thallium-201 reinjection imaging. Preliminary findings for the first 143 patients with ischemic heart disease and perfusion defects at stress imaging are reported. Eighty-eight patients were reinjected at rest after conventional stress-redistribution imaging. Another 55 patients were reinjected at rest on a separate day. After segmental comparison of conventional redistribution versus stress imaging, differences > 1 in the segmental scores on a reduced 3 point scale identified 58 patients with irreversible or mainly irreversible defects (dominant scar pattern) and 85 patients with reversible or mainly reversible defects (dominant ischemic pattern). When reinjection was compared to stress images, 24 patients out of 58 with a dominant scar pattern at the conventional analysis were then assigned to the group with a dominant ischemic pattern. No clinical variables or exercise stress data were found to be significantly different in this patient subgroup. Only 4 out of 85 patients with a dominant ischemic pattern were reassigned to a dominant scar pattern after reinjection scoring. These preliminary results of the SIRT study confirm the consistent problem of scar overestimation by conventional stress-redistribution imaging and the clinical value of the thallium-201 reinjection procedure for differentiating viable from necrotic myocardium.

Dipyridamole-echocardiography: clinical usefulness following interventions

Dipyridamole-echocardiography test response can be expressed not only in a black or white (positive vs negative) code but also, in positive tests, by a gray scale integrating the severity and extent of the dyssynergy as well as the ischemia-free stress time. The recognition of the dyssynergy is important to establish the diagnosis; however, the evaluation of the degree of the induced ischemia, stratified according to spatiotemporal coordinates, is even more important because it accurately predicts the coronary anatomical and functional situation, as well as the prognosis of the individual patient. Furthermore, the "shades of gray" in a positive response have proved useful in assessing the beneficial effects of several interventions: coronary angioplasty; coronary artery bypass surgery; thrombolysis; and medical antianginal therapy. Due to its excellent reproducibility, dipyridamole-echocardiography can play a pivotal role for simple, safe, fast, accurate, and objective assessment of therapeutic interventions, either mechanical or pharmacological, based upon the presence, timing, severity, and extent of dipyridamole-induced dyssynergy.

Accuracy and safety of technetium-99m hexakis 2-methoxy-2-isobutyl isonitrile (Sestamibi) myocardial scintigraphy with high dose dipyridamole test in patients with effort angina pectoris: a multicenter study. Italian Group of Nuclear Cardiology

Clinical and physiologic evidence indicates that maximal coronary vasodilation is not achieved in a large number of patients with use of the standard dose of dipyridamole (0.56 mg/kg body weight over 4 min). The feasibility, safety and accuracy of technetium-99m hexakis 2-methoxy-2-isobutyl isonitrile (Sestamibi) scintigraphy associated with intravenous high dose dipyridamole (0.56 mg/kg over 4 min followed 4 min later by an additional 0.28 mg/kg over 2 min) were evaluated in a multicenter study. Planar myocardial perfusion images were obtained at rest and after dipyridamole in 101 patients with effort chest pain and no prior myocardial infarction. High dose dipyridamole (62 patients) was used when typical chest pain or electrocardiographic (ECG) signs of ischemia, or both, did not occur during or after the standard dose (39 patients). With high dose dipyridamole, 34 patients had pain (18 patients) or ECG signs of ischemia (ST depression greater than or equal to 2 mm) (8 patients), or both (8 patients), whereas the other 28 patients had Sestamibi injection in the absence of symptoms or ECG changes. All patients underwent coronary angiography: 81 had significant coronary artery disease (greater than or equal to 50% reduction of lumen diameter) (affecting one vessel in 38, two vessels in 19 and three vessels in 24 patients) and 20 patients had normal coronary arteries. The overall sensitivity, specificity and predictive accuracy of Sestamibi scintigraphy were 81%, 90% and 83%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of usefulness of high-dose dipyridamole echocardiography and exercise electrocardiography for detection of asymptomatic restenosis after coronary angioplasty

The present study compares the relative usefulness of the maximal treadmill exercise electrocardiography test with the high-dose dipyridamole echocardiography test (echocardiographic monitoring during dipyridamole infusion up to 0.84 mg/kg in 10 minutes) in detecting severe restenosis or coronary artery disease progression (greater than 70% stenosis) in asymptomatic patients 12 months after a primary successful coronary angioplasty. Criteria of positivity were: for the exercise electrocardiography test, an ST-segment shift greater than or equal to 0.1 mV from baseline, 0.08 second from the J point; for the dipyridamole echocardiography test, a transient dyssynergy of contraction, absent or of a lesser degree than that in the baseline examination. The exercise electrocardiography and dipyridamole echocardiography tests revealed a similar feasibility (91 vs 87%, difference not significant). Both tests could be performed in 75 patients. For detection of restenosis or disease progression, or both, the exercise electrocardiography test revealed a sensitivity similar to the dipyridamole echocardiography test (71 vs 71%, difference not significant), but a lower specificity (61 vs 90%). It is concluded that the high-dose dipyridamole echocardiography test is equally feasible but more accurate than the exercise electrocardiography test for noninvasive detection of severe asymptomatic restenosis or disease progression at 1 year after successful coronary angioplasty.

Exercise electrocardiography versus dipyridamole echocardiography testing in coronary angioplasty. Early functional evaluation and prediction of angina recurrence

Recently, we have shown the usefulness of high-dose dipyridamole echocardiography testing (DET) as an exercise-independent method for the evaluation of patients having coronary angioplasty. The purpose of the present study was to determine the value of DET compared with exercise testing in the early functional evaluation after successful percutaneous transluminal coronary angioplasty (PTCA) and in the prediction of late recurrence of angina. We performed DET and exercise testing in 52 consecutive patients both before and after successful PTCA. Criteria of positivity for DET were transient dyssynergy absent or negligible in the baseline examination and exercise testing for an ST segment shift greater than 0.1 mV from baseline. All patients had an angiographically successful PTCA: the percent stenosis went from 78 +/- 7% before to 30 +/- 7% after PTCA. Exercise testing was positive in 49 and 29 patients, respectively, before and after PTCA (94% versus 44%, p less than 0.001). DET was positive in 47 patients before and in 10 after PTCA (90% versus 19%, p less than 0.001). Recurrence of angina was found in 18 patients: 14 of 23 with positive and four of 29 with negative exercise testing after PTCA. With DET, recurrence of angina was found in eight of 10 patients with positive and 10 of 42 with negative DET after PTCA.(ABSTRACT TRUNCATED AT 250 WORDS)

Exercise testing and dipyridamole echocardiography test before and 48 h after successful coronary angioplasty: prognostic implications

The purpose of the present study was to determine the value of exercise testing (ET) and dipyridamole echocardiography test (DET) in the early functional evaluation after a successful coronary angioplasty (PTCA) and in the prediction of angina recurrence. 52 patients underwent ET and DET before and 48 h after a successful PTCA. During a 6-12 month follow-up period they all underwent clinical evaluation. Before PTCA, ET was positive in 49 of 52 patients (94%) and new asynergies were detected by DET in 47 of 52 patients (90%). 48 h after PTCA 23 patients (44%) had positive ET results and 10 had a positive DET response. During the follow-up, 17 patients experienced recurrence of angina. Positive predictive value (PPV) for angina recurrence of ET and DET performed early after the PTCA were, respectively, 57 and 80%. The PPV of ET increased to 88% when electrocardiographic (ECG) positivity was accompanied by angina. Negative predictive values of ET and DET were, respectively, 86% and 79%. Early after PTCA, exercise ECG positivity was not predictive of symptom recurrence while ECG positivity associated with angina revealed a high PPV, similar to that of DET.

Intermittent transdermal nitroglycerin monotherapy in stable exercise-induced angina: a comparison with a continuous schedule

The aim of this study was to investigate nitrate tolerance during continuous treatment with nitroglycerin patches (NTG) as monotherapy, and to assess whether tolerance might be prevented by an overnight nitrate-free interval. Ten male patients, of mean age 53.2 years (range 41-62 years), with pathological coronary angiography and stable exercise-induced angina pectoris took part in a double-blind crossover study (two 15-day periods), during which the continuous and intermittent (12-h nitrate-free interval) application of NTG 20 mg (24 h)-1 patches were compared. Single-blind placebo was given acutely before and at the end of the crossover. Exercise testing was performed on a treadmill according to the Bruce protocol 4 and 12 h after dosing, both during placebo and at the end of the two active treatment periods. In comparison with continuous treatment, the intermittent administration of 20 mg (24 h)-1 NTG patches significantly increased ischaemic threshold and total work time at the 4th and the 12th hour. Night-time withdrawal of NTG transdermal delivery systems determined during the 15-day period a total of 11 night anginal attacks in six out of 10 patients (0.07 attacks per patient per nitrate-free interval).

Usefulness of high-dose dipyridamole echocardiography test in coronary angioplasty

Seventy-four consecutive patients with angina undergoing single-lesion percutaneous transluminal coronary angioplasty were evaluated with high-dose (up to 0.84 mg/kg during 10 minutes) dipyridamole echocardiography test (DET) before angioplasty and when possible, afterward. Angioplasty was clinically or angiographically successful in 63 patients and unsuccessful in 11. Before the procedure, 69 patients had a positive DET. Of these 69 patients, six with clinicall unsuccessful angioplasty had a dipyridamole time (i.e., the time from the onset of dipyridamole infusion to development of asynergy) lower than the 63 patients with clinically successfully angioplasty (4.2 +/- 2.9 vs. 7.0 +/- 2.9 minutes, mean +/- SD, p less than 0.01). In the five patients with angiographically unsuccessful angioplasty (residual stenosis diameter, greater than 50%), coronary stenosis decreased from 89 +/- 10 to 69 +/- 22 (p = NS); DET was positive in all five before and in four of the five after the procedure (100% vs. 80%, p = NS). In the 63 patients with angiographically successful angioplasty, coronary stenosis diameter was reduced from 85 +/- 9% to 30 +/- 10% (p less than 0.01). DET was positive in 58 patients before and in only 16 after the procedure (92% vs. 25%, p less than 0.01). In the 16 patients with positive DET, before and after angioplasty, dipyridamole time increased from 5.6 +/- 2.2 before to 7.3 +/- 2.4 minutes immediately after the procedure (p less than 0.05). After an average follow-up time of 10.8 +/- 5.9 months, angina recurred in eight of 47 patients with negative DET after angioplasty and in 11 of 16 patients with positive DET (17% vs. 69%, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Dipyridamole-thallium 201 scintigraphy in the early post-infarction period. (Safety and accuracy in predicting the extent of coronary disease and future recurrence of angina in patients suffering from their first myocardial infarction)

To evaluate the safety and usefulness of myocardial thallium-201 scintigraphy after intravenous dipyridamole during the early post-infarction period, 35 patients under 60 years of age and with recent first transmural uncomplicated myocardial infarction (27 inferior, 8 anterior) were examined between the 5th and 13th day of hospitalization. Although four patients experienced angina and transient ischemic ST depression during the test, there were no serious complications. Patients were followed for a mean period of 11.4 +/- 6.3 months after hospital discharge. None of the patients experienced recurrent infarction and there were no cardiac deaths. In 11 patients there were reversible perfusion defects in areas different from those of myocardial infarction. Of these patients, seven (one with infarct vessel stenosis only and six with multivessel coronary disease) developed angina during the follow-up: five underwent coronary surgery because of severe angina refractory to full medical therapy. Out of the 24 patients without reversible perfusion defects, only two (with multivessel coronary disease) showed typical angina symptoms. The presence of redistribution on thallium scans was significantly more frequent in patients who developed a recurrence of angina over a period of 11.4 +/- 6.3 months of follow-up (P less than 0.0005). Thus dipyridamole-thallium 201 scintigraphy is a safe, non-invasive stress test which may be used early following uncomplicated myocardial infarction in order to identify patients at risk for the recurrence of angina.

The effects on exercise tolerance of a new transdermal therapeutic system containing nitroglycerine, in patients with stable angina pectoris

In two randomized, double blind, placebo-controlled, within patient, studies, the effects of 4 doses of a new transdermal therapeutic system containing nitroglycerin (TTS-NTG) were studied in a total of 15 patients with stable exercise-induced angina pectoris. A single 24-hour application of TTS-NTG 10 cm2, TTS-NTG 20 cm2 and TTS placebo (1st study: 6 patients) and of TTS-NTG 40 cm2, TTS-NTG 80 cm2 and TTS placebo (2nd study: 9 patients) was applied on 3 different days, and a symptom-limited cycloergometric exercise test was performed 3, 12 (only in the 2nd study) and 24 hours after the application of each treatment. In comparison with placebo, the doses tested in the 1st study induced, at the 3rd hour post-dosing, a decrease in standing systolic blood pressure and an improvement in exercise tolerance which, however, were not statistically significant while the effects at the 24th hour were similar to those of placebo. In the 2nd study, in comparison with placebo, both TTS-NTG doses induced, 3 hours post-dosing, a significant decrease in both lying and standing systolic (P less than 0.01) blood pressure at rest, and a significant (P less than 0.01) improvement in exercise tolerance throughout the 24 hours of application. It is concluded that, in patients with exercise-induced angina pectoris due to coronary artery disease, a single application of TTS-NTG 40 cm2 or 80 cm2 results in a 24-hour increase in exercise tolerance.

[Diagnostic reliability of clinical and instrumental data in identifying the presence of coronary disease in women with chest pain]

The present study was performed to assess the reliability of clinical symptom, rest and exercise electrocardiogram, exercise Thallium myocardial scintigraphy, as well as rest and exercise radionuclide angiocardiography, in order to detect significant coronary artery disease in 85 female patients with chest pain, who underwent coronary angiography. Of these, 54 underwent Thallium myocardial scintigraphy, 53 rest and exercise radionuclide angiocardiography. We have evaluated sensibility, specificity and positive and negative predictive value for each single variable or every possible combination. Within the population examined, Thallium myocardial scintigraphy reaches the highest sensibility (92%), specificity (92.5%), positive predictive (81%) and negative predictive value (97%). In comparison with all other clinical or instrumental parameters, taken either single or in combination. By subdividing the sample in two groups, of 20 and 65 patients respectively on the basis of the clinical symptom angina or thoracoalgy, with different predominance of coronaropathy (60 and 15%), Thallium myocardial scintigraphy is confirmed to be the most reliable diagnostic test (within the angina group sensibility 86%, specificity 100%, positive predictive value 100%, negative predictive value 83%, within the thoracoalgy group sensibility 100%, specificity 91%, positive predictive value 70%, negative predictive value 100%). However, within the thoracoalgy group, a negative maximal exercise test and a normal rest radionuclide angiocardiography detect patients with low probability of coronaropathy (negative predictive value respectively 100% and 93%). Within the angina group only Thallium myocardial scintigraphy significantly increases the predictive value of the angina symptom itself with respect to the presence of coronaropathy (positive predictive value of angina symptom alone 60%, of angina symptom plus Thallium myocardial scintigraphy 100%).

Effectiveness of low-dose heparin in prevention of myocardial reinfarction

728 patients aged 50-75 years who had had Q-wave myocardial infarction 6-18 months previously were enrolled in a randomised, multicentre trial of low-dose heparin in prevention of reinfarction. The control group (365 patients) received their study centres' usual therapy; the heparin group (363 patients) also received subcutaneous calcium heparin (12,500 IU daily). Mean (SD) follow-up was 708 (265) days in the heparin group and 687 (251) in the control group. The reinfarction rate was 63% lower in the heparin than in the control group (4/303, 1.32% v 13/365, 3.56%). The difference in cumulative reinfarction rate between the groups was significant by both drug-efficacy (chi 2 = 3.99, p less than 0.05) and intention-to-treat analysis (chi 2 = 3.84, p = 0.05). Heparin treatment reduced the cumulative general mortality rates by 48% on drug-efficacy analysis (chi 2 = 3.88, p less than 0.05) and by 34% on intention-to-treat analysis (chi 2 = 2.05, not significant). Cardiovascular mortality was also reduced (33%) but not significantly. However, fatal events attributable to thromboembolism (fatal reinfarction, stroke, pulmonary embolism) were significantly less frequent in the heparin than in the control group (1 v 7, p less than 0.05). 60 patients (16.5%) discontinued heparin treatment, but only 23 patients (6.3%) stopped because of side-effects. Low-dose heparin appears to be effective, safe, well tolerated, and free from haemorrhagic risk for the prevention of myocardial reinfarction.

Indications for surgical treatment in post-infarction angina

In order to evaluate whether or not criteria for surgical revascularization in patients with early post-infarction angina (EPIA) should be different from those commonly used for patients with angina, the incidence and prognostic implications of EPIA were analysed in 188 AMI patients in Killip's class I or II on admission. Sixty-two patients (33%) complained of EPIA (Group I) and 126 patients were symptom-free (Group II). There were no differences between the two groups in in-hospital and late mortality and reinfarction. On the contrary, severity of angina was significantly associated with the occurrence of in-hospital and late cardiac death, reinfarction and revascularization procedures. EPIA patients underwent revascularization procedures significantly more frequently than group II patients, both during hospitalization (29% versus 1%; P less than 0.001) and follow up (10% versus 1%; P less than 0.01). Coronary artery involvement was significantly more severe in group I than in group II and in the operated patients compared with the non-operated ones. Our data suggest that the severity of angina should be the leading criterion for surgery, as it is able to identify most of the patients with severe coronary artery disease and poor prognosis.

[Assessment of coronary stenosis by myocardial scintigraphy with thallium-201 after dipyridamol infusion]

After a 4 minute i.v. dipyridamole infusion (0.14 mg/Kg/min) serial Thallium-201 scans were obtained in 45 patients, without myocardial necrosis, undergoing coronarography. Twelve patients had effort angina, 6 rest angina, 14 effort associated with rest angina, 13 had atypical chest pain. Thirty-two patients had a 50% or greater stenosis of 1 or more coronary artery (8 had three vessels disease, 7 two vessels, 17 one vessel); 13 patients had no significant coronary stenosis ("control group"). The test induced electrocardiographic signs of ischemia in 18 patients, all with significant coronary stenosis, 15 of them experienced angina too. Sensitivity of Thallium-201 for detecting coronary artery stenosis was 94% (30 of 32) and specificity was 85% (11 of 13). In the group of the 17 patients with one vessel disease we obtained a sensitivity and specificity of 100% (17 of 17). We conclude that Thallium-201 myocardial imaging after pharmacologic vasodilatation with dipyridamole is a highly sensitive and specific test for detecting coronary artery stenoses without necessary overt ischemia. In fact dipyridamole, as consequence of its important coronary vasodilatation, produces differences in myocardial perfusion with relative perfusion defects detectable with Thallium-201 imaging.

[Myocardial revascularization in patients with severe ventricular impairment. Short-term follow-up]

To assess the influence of aorto-coronary bypass grafting on surgical risk and short-term survival of patients with marked impairment of left ventricular (LV) function, we evaluated--among 435 patients who underwent coronary bypass surgery between January 1981 and December 1982--22 cases with: LV ejection fraction (EF) less than or equal to 0.35 (mean 0.27 +/- 0.06), LV end-diastolic pressure greater than or equal to 15 mmHg (mean 19.9 +/- 6.9 mmHg.), presence of three or more dysfunctional (hypokinetic or akinetic) segments on biplane LV angiography, three vessels disease in 90.1%. All patients but two had angina refractory to medical therapy. Operative mortality rate was 4.5%. Perioperative non fatal infarction rate was 9.1%. There were three late deaths. Mean duration of follow-up was 10.5 +/- 8.3 months with a survival of 81.8%. In the survivors we observed: dramatic improvement in respect to angina (94.5% are asymptomatic) and quality of life; exercise performance improvement (75% of patients have a functional impairment less than or equal to 30% at treadmill test); significant improvement in global and segmental LV function (mean echocardiographic EF 0.37 +/- 0.10, p less than 0.001). Because of relative low surgical risk and encouraging short-term results, aortocoronary bypass grafting can be performed even in patients with important LV disfunction, when associated with severe angina.

Percutaneous transluminal coronary angioplasty. Critical assessment of preliminary results

Since June 1981 until July 1983, 40 percutaneous transluminal coronary angioplasty procedures in 38 patients have been performed. Results in the whole series are as follows: stenosis crossed in 33 patients (83%); balloon inflation done in 31 (78%), not done in 2 due to clinical instability induced by crossing of the stenosis; successful dilatation obtained in 25 patients (63%); emergency bypass surgery in 6 patients (15%) with 2 perioperative myocardial infarctions; no deaths. The whole series can be subdivided in two groups by the following parameters: premedication by nitrates (A) or by verapamil (B); temporal concentration of the procedures: 1/month up to February 83 (A), 3.7/month thereafter (B). Results are different in the two groups: 21 attempts in 21 patients: stenosis crossed in 14 cases (67%), balloon inflated in 12 (57%), successful dilatation obtained in 8 patients (38%), emergency bypass in 5 patients (24%). 19 attempts in 17 patients (2 vessel angioplasty in 2 patients): stenosis crossed and balloon inflated in 19 (100%), successful dilatation in 17 cases (89%), uncomplicated emergency bypass in 1 patient (5%). On the basis of personal more recent results an optimistic attitude towards the percutaneous transluminal coronary angioplasty is justified.