Multiple atherosclerotic plaque rupture in acute coronary syndrome: a three-vessel intravascular ultrasound study

BACKGROUND

To test the hypothesis of general atherosclerotic plaque destabilization during acute coronary syndrome (ACS), the present study sought to analyze the 3 coronary arteries by systematic intravascular ultrasound scan (IVUS).

METHODS AND RESULTS

Seventy-two arteries were explored in 24 patients referred for percutaneous coronary intervention after a first ACS with troponin I elevation. Fifty plaque ruptures (mean, 2.08 per patient; range, 0 to 6) were diagnosed by the association of a ruptured capsule with intraplaque cavity. Plaque rupture on the culprit lesion was found in 9 patients (37.5%). At least 1 plaque rupture was found somewhere other than on the culprit lesion in 19 patients (79%). These lesions were in a different artery than the culprit artery in 70.8% and were in both other arteries in 12.5% of these 24 patients. Complete IVUS examination of all 3 coronary axes in patients who had experienced a first ACS revealed that multiple atherosclerotic plaque ruptures were detected by IVUS; these multiple ruptures were present simultaneously with the culprit lesion; they were frequent and located (in three quarters of cases) on the 3 principal coronary trunks; and the multiple plaque ruptures in locations other than on the culprit lesion were less severe, nonstenosing, and less calcified.

CONCLUSION

Although one single lesion is clinically active at the time of ACS, the syndrome seems nevertheless associated with overall coronary instability.

[Multiple ruptures of atherosclerotic plaques in acute coronary syndrome. Endocoronary ultrasonography study of three arteries]

The aim of this study was to assess the three coronary arteries systematically by endocoronary ultrasonography in patients with unstable angina to check the hypothesis of global destabilisation of atherosclerotic plaques in acute coronary syndromes (ACS). Sixty two coronary arteries were examined (2.6 per patient). Fifty plaque ruptures were diagnosed (2.08 per patient). Rupture of a plaque of the culprit lesion of the ACS was clearly detected in 9 patients (37.5%). At least one ruptured plaque on a site other than the culprit lesion was observed in 19 patients (79%), on another artery in 70.8% of cases and on two other arteries in 12.5% of cases. A complete endocoronary ultrasonic examination of the three coronary arteries in patients with a first ACS demonstrated that: multiple atherosclerotic plaque rupture may be detected by endocoronary ultrasonography; these multiple plaque ruptures occur simultaneously with the culprit lesion; they are frequent and can be situated on the three main coronary vessels and multiple plaque rupture other than the culprit lesion are less severe, non stenotic and less calcified. Thus, although a single lesion is clinically symptomatic, ACS seems to be associated with global coronary instability.

[Subacute infectious endocarditis due to the agent of cat scratch fever: Bartonella henselae]

The diagnosis of severe mitral stenosis with left atrial thrombus was rectified at valvular replacement in a 48-year old immuno-competent man who was a cat owner. The mass in the left atrium was, in fact, a large endocarditic vegetation. Pre- and postoperative blood cultures were negative as was culture of the excised mitral valve. The diagnosis of infectious endocarditis (IE) due to Bartonella Henselae was made from a positive serological test (1600) and identification of the germ by genetic amplification. Antibiotic therapy was continued for 6 months and the patient was cured with a follow-up of 4 years. Bartonella Henselae IE is very rare (14 reported cases) and affects mainly the aortic valve, often giving rise to very large vegetations which, in half the cases, are complicated by systemic emboli. Germs like Batonella are sensitive to most antibiotics, especially the aminosides and macrolides. In Bartonella Henselae IE, valve replacement is the rule (13 out of 14 cases) and the prognosis is usually good. Sero-diagnosis of Bartonellosis should be part of the systematic investigation of all blood culture negative IE.

[Communication between the left ventricle and the right atrium in infectious endocarditis. Diagnosis using Doppler-echocardiography]

The diagnosis of a communication between the left ventricle and right atrium was made by transthoracic and transoesophageal echocardiography in a 67 year old man with a recurrence of a methicillin-resistant staphylococcus aureus infectious endocarditis complicating aortic valve replacement with a bioprosthesis seven weeks previously. This diagnosis was confirmed at surgery; the left ventricular-right atrial communication was closed by suturing its edges and a new aortic valve prosthesis was implanted. Unfortunately, the patient died 4 months later of myocardial dysfunction although the infectious endocarditis seemed to have been sterilised by antibiotic therapy. Doppler echocardiography, especially using the transoesophageal approach is the best diagnostic method for rare complications of infectious endocarditis, usually of the aortic valve, the prognosis of which is improved by early surgery and appropriate antibiotic therapy for the causal organisms.

[Myocardial infarction in the elderly. Comparison between 2 groups of patients over 75 and under 65 years of age]

To define the clinical characteristics, prognosis and treatment of myocardial infarction (MI) in the elderly, we retrospectively compared the files of 101 patients aged > or = 75 years (mean: 82 +/- 4 years) and of 120 others aged < or = 65 years (mean: 55 +/- 4.7 years). The figures corresponding to younger patients are presented in brackets. The elderly group included 60.4% women (5%: p < 0.001), 58.9% hypertensive subjects (38.3%: p = 0.005); 30.4% diabetics (11.7%: p = 0.0013) and 12.6% smokers (66.1%: p < 0.001); 20.8% of the elderly had a history of MI (10%: p = 0.002), 15.8% of arteriopathy of the lower limbs (8.3%: p = 0.001) and 6.9% of cerebrovascular accident (1.7%: p = 0.02). Elderly patients were admitted after an average of 26.6 hours (10.4 hours: p < 0.001). Only 56.4% (79.2%) reported typical MI pain, 22.8% (7.5%) had a painless form, 31.8% (4.2%) an initial left ventricular failure, 21.8% (7.5%) a global cardiac dysfunction and 20.8% (4.2%) a cardiogenic shock (p < 0.001 for all comparisons). 63.4% had an anterior MI (40.8%: p < 0.001), 40.6% a Q-form (29.6%: p = NS) and 22.2% an atrial fibrillation (0.8%: p < 0.001). Serum myoglobin and total CK concentrations were significantly lower in elderly subjects. 20.8% of them received beta-blockers (86.7%), 43.6% aspirin (80%), 14.6% oral anticoagulant (56.7%), but 63.4% were given diuretics (25.2%) and 31.7% digitalis alkaloids and positive inotropic drugs (6.7%) (p < 0.001 for all these comparisons). Heparin, nitrates, calcium channel blockers, ACE inhibitors and antiarrhythmics were prescribed as often regardless of age. Only 10 elderly patients (9.9%) were treated with thrombolytics (77: 65%: p < 0.001); 6 (5.9%) underwent coronary angiography (43: 35.8%: p < 0.001), 2 (2%) angioplasty (11: 9.2%) and one (1%) coronary bypass surgery (12: 10%). 35 elderly patients (34.7%) died while in hospital (5: 4.2%), 22 suddenly, 10 in cardiogenic shock and 3 due to arrhythmias. 38 cases (37.8%) of heart failure (21: 17.5%), 21 (20.8%) recurrences of coronary insufficiency (8: 6.7%) and 11 (10.9%) mechanical complications of MI (4: 3.3%) were also observed (p < 0.001 for all these comparisons). Due to lack of sufficient data, we could not define the status of the surviving patients discharged from hospital. The wider use of thrombolytics, angiography and angioplasty (coronary bypass surgery still having a heavy mortality and morbidity) is probably the best way to improve the prognosis of MI in the elderly.

[Value of mass dosage of the MB isoenzyme of creatinine phosphokinase in the diagnosis of recent myocardial infarction]

In 391 patients admitted 3.7 hours (h) (median) after experiencing infarct-like pain, kinetic monitoring of CK-MB "mass" (threshold: 7 micrograms/l), myoglobin (threshold: 90 micrograms/l) and total CK (threshold: 290 micrograms/l) was carried out at the time of admission and after 1.5, 3, 6, 9, 12, 24 and 48 h. When myocardial infarction (MI) was treated conventionally (102 patients). CK-MB peaked 11 h (median) after the onset of pain, later than myoglobin (9 h), but before total CK (12 h). The peak of the markers was higher in Q+ than in Q-MI (p < 0.05). When MI was treated by thrombolytic medications (44 patients), the increases in CK-MB, myoglobin and total CK were larger, and occurred sooner (peaks 9, 6 and 6 h, after the onset of pain respectively), but did not last as long. In 245 patients who had not had MI (including 123 with spontaneous angina), the levels of the three markers remained stable and well below the decision thresholds. The sensitivities of CK-MB, myoglobin and total CK were respectively 47.1, 51.8 and 34.8% at the time of admission, 67.3, 82.7 and 57.1% after 3 h and 83.1, 76.9 and 88.9% after 6 h. The combined determination of CK-MB and of myoglobin had a higher sensitivity (67.7% at the time of admission, 84.9% after 1.5% and 88.2% after 3 h: but most of this gain was due to myoglobin. The specificity of the three markers and their diagnostic accuracy are comparable. In the course of recent MI, the kinetics of CK-MB mass are thus slower than those of myoglobin, but a little faster than those of total CK. The choice of the most effective biochemical marker depends upon the interval between onset of chest pain and hospitalization of the patient. Repetition of the determinations improves the diagnostic situation.

[Ilio-femoral vein thrombosis treated with tissue plasminogen activator in a pregnant woman]

A 27-year-old woman, after 31 weeks of amenorrhoea during her second pregnancy, developed a left external iliac and femoral deep vein thrombosis, confirmed by venous ultrasonography and magnetic resonance imaging. The infusion of tissue plasminogen activator (rt-PA: 1.2 mg/kg, i.e. 80 mg over 3 hours), on the 2nd day, allowed revascularization of the femoral junction, while the external iliac vein remained occluded. The patient did not develop pulmonary embolism or haemorrhage, particularly obstetric haemorrhage. The subsequent pregnancy was uneventful until delivery, six weeks later, of a normal child. Three years later, the patient has no sequelae of her deep vein thrombosis. When required by the patient's condition, it seems that rt-PA can be used to treat severe deep vein thrombosis during pregnancy, either isolated or complicated by pulmonary embolism. Very rigorous cardiological, obstetric and laboratory surveillance is essential. A sufficient dosage, identical to that used in clinical settings other than pregnancy and a brief treatment duration (2 to 3 hours) are probably more effective and more reliable than lower doses continued for several days. However, the risk of haemorrhage remains difficult to predict and its prognosis, especially foetal, is often very poor. A larger series of cases is therefore necessary before this drug can unreservedly recommended in pregnant women.

[Cerebral embolism disclosing a left intraventricular thrombus 6 years after atypical infarction]

The authors report a case which is unusual because of the late presentation, as a cerebral embolism, of a left intraventricular thrombus six years after an infarction. This thrombus was absent at the acute stage of the infarction. The conditions surrounding the development of a thrombus after an infarction are reviewed. This is a common complication at the acute stage of an anterior infarction, notably when there is apical akinesia. The late onset of these thrombi has not been extensively studied in the literature. This would appear to be a fairly rare event but which, as shown by our case, pleads in favour of very prolonged anticoagulant treatment after certain myocardial infarctions.

[Effect of tobacco smoking on the incidence of recurrent myocardial infarction. A retrospective study of 208 cases]

Two hundred and eight patients, less than 60 years of age at the time of their first myocardial infarction (MI), which occurred between 1 July 1976 and 30 September 1982, and with a mean recurrence-free follow-up period of 3450 +/- 142 days, were included in a retrospective survey. This concerned the outcome of their coronary artery disease and the persistence of vascular risk factors, notably their tobacco consumption, the extent and forme of which was detailed. This study showed: 1) the mortality rate was 8.8%, 2) 78.4% of the patients smoked before their infarction, 3) 76% of the smokers stopped smoking after this event. The risk of recurrence of infarction was higher amongst smokers. After 5 years, 51.6 +/- 15% of the subjects who had not reduced their daily tobacco consumption had suffered another MI, versus 21.5 +/- 3% of those who had reduced it by 1 to 50%, 16.9 +/- 6% of those who had never smoked and only 10.5 +/- 6% of those who had reduced it by more than 50% or had stopped smoking (p less than 0.02). The relative risk of recurrence of infarction in persistent smokers was 4.4 times that in subjects who had stopped smoking. However, no significant difference was found between the mortality in the various subgroups. In addition to smoking, only two factors were found to significantly promote the onset of a fresh MI: an initial infarction with no Q wave (p = 0.007), and the persistence of spontaneous angina pectoris (p = 0.0009).

[Coronary insufficiency caused by atherosclerosis. Current pathogenic concepts, clinical, angio-anatomic correlations and therapeutic deductions]

The multiplicity of clinical expressions of coronary artery failure results from the interaction between three processes which varies from one patient to another and from one time to another in a given patient. The three processes involved are: atheromatous coronary stenosis, arterial spasm and the development of a fibrino-thrombocytic thrombus. In stable angina pectoris, atheromatous narrowing, with smooth, regular outlines, no endothelial injury and little likelihood of complication by thrombosis predominates. In contrast, labile angina and myocardial infarction give rise to the same lesions: usually irregular stenoses, with a narrow neck and irregular outline. They correspond histologically to the rupture of an atheroma plaque, frequently complicated by the appearance in situ of a clot. In the authors' experience, complete arterial occlusion ensues in three out of four cases. The rate at which aggravation progresses and the variable degree of collateral circulation explains why a whole range of intermediate clinical expressions are possible, ranging from labile angina to sudden death of ischemic origin, and including various forms of infarction (both with and without the Q wave). Healing of these lesions may also be observed, usually resulting in progression of the coronary stenosis and sometimes of modification of left ventricular function of variable duration (myocardial stunning or hibernation). The importance of thrombotic phenomena in triggering the most serious forms of coronary artery failure (labile angina and myocardial infarction) provides a more precise identification of the place of thrombolytic treatment. In addition, it appears that there is no point in emergency revascularization of the ischemic myocardium. However, despite recent clinical progress, coronary artery disease remains a worrying illness which calls for primary prevention measures. Such measures must be undertaken as soon as possible if they are to be effective.

[Angiographic morphology of the coronary arteries after a recent myocardial infarction treated by intravenous thrombolysis]

Thirty patients (26 men, 4 women) aged from 32 to 73 years (mean 54 years) who developed anterior (14 cases) or posterior (16 cases) myocardial infarction received intravenous streptokinase in doses of 1,500,000 units 2 to 10 hours (mean 4 hours) after the onset of infarction. Coronary angiography, performed 18.6 days on average after thrombolysis, showed a distinct predominance of asymmetrical stenosis with irregular walls and a narrow neck (10 cases, 33 p. 100) or of complete occlusion (12 cases, 40 p. 100) in the artery responsible for the infarction. Complete occlusion probably was the ultimate stage of stenosis. In contrast, the various angiographic images observed in arteries unrelated to the infarction were evenly distributed. The radiological morphology of coronary arterial lesions after a recent infarction is suggestive of ruptured atheromatous plaque, sometimes complicated by thrombosis in situ. Identical images are seen in unstable angina. These findings indicate that one single therapeutic approach should be applied to the most severe types of coronary disease due to atherosclerosis.

[An overlooked electrocardiographic sign of acute embolic cor pulmonale: elevation of the ST segment in right precordial leads]

Elevation of the ST segment in the right precordial leads may be associated with electrocardiographic signs of acute cor pulmonale. This sign, which we have observed in 77 cases of moderate to severe pulmonary embolism (greater than 1.3 per cent of cases), is a very early but transient sign of usually moderate to severe pulmonary embolism. In the presence of this sign, the diagnosis of pulmonary embolism with acute cor pulmonale should be proposed at the same time as more common aetiologies such as coronary insufficiency and pericardial disease.

[Auriculo-ventricular block and pregnancy]

20 cases of pregnancy in women with complete atrioventricular block (AVB) (12 patients) or with permanent pacemakers (8 patients) were observed in a French cooperative series and compared with I30 previously reported cases. Most patients were asymptomatic but an increase in the number of syncopes during gestation might be observed : 4 out of 12 in our series. Although AVB remains functionally latent during pregnancy, regular cardio-obstetric follow-up is advised. Hospital admission a few days before the expected date of delivery is desirable, and it is essential that the patients are delivered in department specialised in high risk pregnancies. The need for prophylactic temporary pacing during delivery is not universally accepted. On the other hand, dizziness and syncope are clear cut indications for permanent cardiac pacing ; programmable pacers are excellent choices in young women of childbearing age ; nuclear pulse generators (Pu 238) do not seem to expose the mothers or foetus to serious complications. Rejection of pulse generators during pregnancy is rare. Nearly all mothers with AVB, whether paced or not, now have normal pregnancies resulting in normal viable children. This conduction defect is not therefore an indication for therapeutic abortion.

Delayed semielective coronary bypass surgery for unstable angina pectoris: clinical follow-up and results of postoperative treadmill exercise

Eighty patients with continued or repeated episodes of chest pain at rest and transitory ischemic electrocardiographic (ECG) changes were classified as having unstable angina pectoris. Following 10 days of intensive medical therapy, including beta blockade, all unerwent coronary arteriography. Medical treatment completely relieved the chest pain in 43 patients (Group I, 54 percent). In 37 patients (Group II, 46 percent) angina recurred within a week of admission (12 patients) or later (25 patients). Seventeen patients were not operated upon (nine were inoperable, four refused operation, and in four operation was not recommended). Sixty-three underwent saphenous vein bypass grafting either following a month of medical therapy (Group I) or within 24 to 48 hours of recurrent angina (Group II). The over-all operative mortality rate was 1.6 percent (1 patient) and the incidence of peroperative infarction was 11 percent. Of the 62 operative survivors, 71 percent were asymptomatic (mean follow-up period 22 months). The incidence of late operative myocardial infarction was 5 percent. Of 44 operative survivors tested by treadmill ECG, 66 percent had a negative response. Thirteen patients underwent postoperative angiographic evaluation (mean, 19.5 months). The over-all patency rate was 84 percent, and in 92 percent of patients at least one graft was patent. Thus, after stabilization by medical treatment, bypass operation could be performed with a low operative mortality rate and the long-term results compare favorably with those achieved with chronic stable angina.

[Endocarditis due to staphylococcus aureus during cardiomyopathy]

In a patient suffering from obstructive cardiomyopathy (IHSS), the onset of septicaemia due to staphylococus aureus was accompanied: 1. by the appearance of massive mitral incompetence and of cardiac failure; 2. by a marked reduction in the left intra-ventricular pressure gradient; 3. by acute reversible renal failure (interstitial nephritis); 4. by a glomerulonephritis with immune complexes deposits. After the septicaemia had been treated, replacement of the mitral valve by a disc prosthesis of Lillehei was carried out. Twenty months after the operation, the patient was completely asymptomatic, and catheterisation showed that the left intra-venticular pressure gradient had disappeared, as had the haemodynamic signs of cardiac failure.

Treatment of post-myocardial infarction angina by intra-aortic ballon pumping and emergency revascularization

Twenty-one patients with postinfarction angina (2 to 15 days after acute myocardial infarction) unresponsive to medical therapy were treated by intra-aortic balloon pumping (IABP). Anginal pain and electrocardiographic (ECG) ST-segment changes were prevented in all patients. Coronary angiograms were obtained during IABP without complication and confirmed severe coronary artery disease. Of the four nonoperated patients, three had reinfarction and two died of cardiogenic shock. Seventeen patients underwent aorta-coronary bypass grafting, associated with aneurysmectomy in two patients and closure of a ventricular septal defect in one. Sixteen patients survived the operation. All survivors are in clinically improved condition and 14 are pain free from 9 to 28 months postoperatively, but three have mild heart failure.

[Emergency myocardial revascularization with assisted circulation for early extension of infarction]

In order to reduce the oxygen consumption of the myocardium and preserve the areas around the infarction, still alive but undergoing ischemia, 8 patients with early extension of their infarction were placed under circulatory assistance by intra-aortic counter-pulsation. In 8 patients, the pain disappeared and did not recur, permitting left ventriculography and coronary arteriogrpahy. This examination is often considered high risk, but in no patient in our series, during the acute phase of myocardial infarction, were there any complications. 6 patients underwent operation, and aortic counter-pulsation was used during the post-operative period. In all, eight coronary by-pass operations were carried out and, in one case, part of the ventricular wall was resected. All patients are still alive, none have heart failure or residual angina; the follow-up period is now 2 years for the first case.