[Perspectives in cardiology: evidence of efficacy in atrial fibrillation and hopes in acute coronary syndrome]

New antithrombotic drugs, antithrombin or anti Xa, will probably be very useful in cardiology. Two directions are interesting: in one hand atrial fibrillation, in which the unmet need concern drugs as effective as vitamine K antagonists but easier to use. On the other hand, in acute coronary syndrome the situation is different, there are many antithrombotic drugs available but there is still a place for innovative drugs which could provide a gain in terms of efficacy, but the hemorrhagic risk must remain acceptable. In atrial fibrillation, the RELY trial, performed in 18,113 patients has demonstrated, as compared to warfarin, a non inferiority of dabigatran at the dose of 110 mg BID and a superiority of dabigatran at 150 mg BID with a reduction of 34% of the primary endpoint, i.e.stroke and systemic embolism.

Pathophysiology of atrial fibrillation: insights into the renin-angiotensin system

INTRODUCTION

Atrial fibrillation is, to date, a major problem of public health with an important cost in the health care system.

DISCUSSION

The therapeutic strategies for atrial fibrillation are complex and their outcomes have been disappointing globally. New ablative techniques have brought important advances but the patient's profile has to be taken into account in the choice of the therapeutic strategies. The renin-angiotensin system plays a major role in the phenomena of remodelling following the onset of atrial fibrillation.

CONCLUSION

Drugs blocking the renin-angiotensin system can have a real place in the treatment of atrial fibrillation, not only to maintain sinus rhythm but primarily to prevent cardiovascular accidents in these patients with atrial fibrillation and in some cases to prevent the occurrence of atrial fibrillation, for example in hypertensive patients.

Relation of depressive mood to plasminogen activator inhibitor, tissue plasminogen activator, and fibrinogen levels in patients with versus without coronary heart disease

The increased risk of coronary heart disease (CHD) associated with depression is well documented. We hypothesized that impaired fibrinolysis is involved in this link. To explore the association of depressive mood and/or vital exhaustion with various measurements of fibrinolysis activity, 231 men (40 to 65 years old; 123 without CHD and taking no medication and 108 with documented CHD), completed the Center of Epidemiologic Studies Depression Scale and the Maastricht Questionnaire for vital exhaustion. Using classic cut-off points (Center of Epidemiologic Studies Depression Scale score >or=17, Maastricht Questionnaire score >or=8), 6.5% and 9.8% of subjects without CHD and 38% and 48.1% of those with CHD were classified as depressed and exhausted, respectively. Patients with CHD were older, had a higher body mass index, and higher levels of total cholesterol, glucose, plasminogen activator inhibitor 1 (PAI-1), tissue plasminogen activator (t-PA) antigen, and fibrinogen; 47% were treated for hypertension. Depressed subjects had higher levels of PAI-1 activity (p = 0.006) and exhausted patients had higher levels of PAI-1 activity (p = 0.011) and fibrinogen (p = 0.009). After adjusting for clinical condition (with or without CHD), smoking, hypertension, triglyceride concentration, and body mass index, PAI-1 activity remained higher in depressed subjects (p = 0.03). This association persisted after further adjustment for vital exhaustion or for t-PA antigen and fibrinogen levels. t-PA antigen and fibrinogen levels were not associated with depressive mood in multivariate analyses. No fibrinolytic variable was associated with vital exhaustion in multivariate analyses. In conclusion, depressive mood, but not vital exhaustion, is associated with higher levels of PAI-1 activity, suggesting a possible impairment of fibrinolysis and indicating a potential additional mechanism by which depressive mood may act as a cardiovascular risk factor.

[Physiopathology of myocardial infarction: the acute coronary occlusion]

Rupture of the atheromatous plaque, thrombosis and local vasoconstriction are involved in the genesis of acute myocardial infarction. The vulnerability of the plaque depends on its histological structure. Its fragility is related to the size of the lipid core, the thinness of the fibrous capsule and the inflammatory reaction. External aggression favourites rupture. This triggers both thrombogenesis by bringing the blood cells into contact with thrombogenic subendothelial factors and local vasoconstriction due to endothelial dysfunction. Although rupture of the plaque is an unpredictable event, there is a circadian variability the highest incidence of infarction being between 6 a.m. and midday. Comprehension of the physiopathology of myocardial infarction has opened up new therapeutic approaches which should reduce the incidence of plaque rupture. Prevention is based on stabilisation of the plaque by dietary hygiene, lipid-lowering drugs and, maybe, in the future, by local application of antisense oligonucleotides. Finally, anti-aggregant therapy (aspirin or anti-GIIb-IIIa) could prevent the formation or extension of the thrombus.

[Diagnosis, course and prognosis of pulmonary arterial hypertension]

Pulmonary arterial hypertension (PAHT) is defined by an increase in mean pulmonary artery pressure above 20 mmHg. Its diagnosis is often easy by cardiac echo-Doppler. Hemodynamic investigation is required in non-echogenic patients or in order to define the type of PAHT: pre- or post-capillary. It is important to determine, on the basis of non-invasive clinical and paraclinical (echocardiography) studies, those patients in whom catheterisation is indicated. PAHT may be due to chronic respiratory disease, left heart disorders, congenital heart disease or follow pulmonary embolism. It is sometimes apparently primary. The prognosis of PAHT depends upon its etiology: when PAHT is secondary to heart disease, it reflects worsening of the causative cardiac problem, which must be corrected. PAHT is a prognostic factor in chronic obstructive lung disease. The course is particularly grave in primary PAHT.

Lack of effects of trimetazidine on systemic hemodynamics in patients with coronary artery disease: a placebo-controlled study

Trimetazidine has been shown to improve anginal symptoms and exercise tolerance in patients with coronary artery disease (CAD). To determine the hemodynamic effects of trimetazidine, systemic hemodynamics were studied in 15 patients suffering from CAD (12 male, 3 female, mean age +/- SEM = 58.6 +/- 1.8 years). Cardiac index was determined by thermodilution method. Left ventricular and aortic pressures were measured using micromanometers (Miller Instruments). After basal measurements, patients were randomly given either placebo (n = 5) or one of two therapeutic doses of trimetazidine 1 mg.kg-1 (n = 5) or trimetazidine 1.5 mg.kg-1 (n = 5) in a double-blind procedure. Data were recorded 5, 10 and 20 min after intravenous drug bolus. Throughout the procedure, the evolution of systemic hemodynamic parameters was not statistically different between the three groups, in particular heart rate, cardiac index, systolic, diastolic and mean aortic pressures, end-diastolic ventricular pressure, mean capillary wedge pressure, pulmonary artery pressures or systemic vascular resistances. We conclude that, unlike other antianginal drugs (particularly beta-blockers, nitrates and calcium-channel inhibitors), trimetazidine does not modify systemic hemodynamics in patients with CAD. These results are consistent with a direct effect of trimetazidine on the ischemic myocardial cell previously reported.

[Quantitative thallium myocardial tomoscintigraphy. Value of intravenous infusion of dipyridamole after negative submaximal exercise test]

Patients with suspected coronary artery disease are sometimes unable to exercise adequately (85% of age calculated maximal heart rate) to validate their ergometric stress test. Some groups suggest performing dipyridamole scintigraphy from the outset but then the information provided by exercise stress testing is lost. The aim of this study was to compare scintigraphies performed after exercise alone and after exercise combined with dipyridamole using a method of quantification. Thirteen patients with ischaemic heart disease without necrosis (coronary lesions greater than 75% luminal narrowing in: 7 right coronary, 10 left anterior descending, 3 left circumflex arteries and 1 left main coronary artery with 50% luminal narrowing) underwent exercise stress testing followed by Thallium imaging. One week later, the same exercise stress test was performed followed by an intravenous injection of dipyridamole and Thallium scintigraphy. The circumference of the radioactivity was traced and the surface of each segment calculated in three different short axis views, subdivided into 4 segments (anterior, lateral, inferior and septal walls). Any segment vascularised by a stenosed coronary artery was considered to be underperfused (105 segments). The ratios of the surfaces of underperfused/normal segments were compared using the two study protocols. Segments of the same wall in the 3 short axis views were grouped in the same myocardial zone. Thirty five myocardial zones were thus obtained: 25 zones were more underperfused after combining exercise and dipyridamole than after simple exercise stress (p = 0.014). The average increase in underperfusion after the combined exercise-dipyridamole was 12.4% compared with 5.5% after exercise alone (p = 0.03). Secondary effects were minimal.(ABSTRACT TRUNCATED AT 250 WORDS)

[Enoximone in the hemodynamic evaluation before heart transplantation. A new test]

A better selection of patients referred for cardiac transplantation should lead to better surgical results. The presence of severe and irreversible pulmonary hypertension is an important factor and its pretransplantation assessment requires pharmacodynamic testing with vasodilators and dobutamine. The aim of this study of 10 patients in congestive cardiac failure referred for cardiac transplantation was to evaluate enoximone in this indication by comparing it with sodium nitroprussiate (3 micrograms/kg/mn). Intravenous enoximone (total dose of 1.5 mg/kg) increased the cardiac index (+49%; p less than 0.01), slightly reduced the mean systemic blood pressure (-8%; p less than 0.05) whilst inducing a greater reduction in systemic arterial resistances (-36%; p less than 0.01); the fall in mean blood pressure was less than with sodium nitroprussiate (-23%; p less than 0.01). Myocardial oxygen consumption (rate-pressure product) did not increase in contrast to the effect of dobutamine (+21%; p less than 0.01). There was a significant reduction in pulmonary arteriolar resistances (p less than 0.01) with all three drugs but the interpretation of this response and its prognostic significance in patients with a low cardiac output and persistent pulmonary hypertension are discutable even when pulmonary arteriolar resistances are less than 6 Wood units. The value of using an inotropic agent such as Dobutamine or Enoximone is to unmask fixed pulmonary hypertension which may be missed in patients with low cardiac output even with vasodilator drugs, and also to mimic the haemodynamic result of transplantation. In this indication Enoximone may be used like Dobutamine but with the advantage of not increasing myocardial oxygen consumption and being probably less arrhythmogenic.

[Phosphodiesterase inhibitors]

Phosphodiesterase III inhibitors constitute a new therapeutic group for congestive cardiac failure. They inhibit the degradation of cyclic adenosine monophosphate and increase the intracellular calcium. They have a double inotropic and vasodilator haemodynamics occurs without any increase in the myocardial effect. The improvement in the consumption of oxygen. The beneficial haemodynamic effect seems to last over a medium period of time, but the survival in the long term treatment is not yet known.

[Short-axis thallium 201 tomography. Changes in the isotope fixation on the circumference of the left ventricle]

Several authors have studied variations in myocardial thickness on short-axis sections cut through healthy postmortem hearts. The circumferential profiles showed a series of minima and maxima, with a minimum at the septum, a maximum at the anterior interventricular junction and another at the anterolateral papillary muscle, a minimum at the inferior wall followed by a maximum at the posterior papillary muscle, then at the posterior interventricular junction, after which came a septal minimum again. When examined by short-axis thallium 201 tomography, the left ventricle does not look like a ring of even density. The purpose of this study was to try and explain the changes in density observed by variations in thickness and to devise a quantification method that would take anatomical features into account. 23 patients with normal coronary angiography underwent thallium 201 scanning after exercise. Circumferential profiles were drawn from short-axis sections with the angle on the abscissa and the number of sections on the ordinate. 29 other patients with a more than 75 p. 100 stenosis of coronary vessels (anterior interventricular artery 15, right coronary artery 10, circumflex artery 8, diagonal artery 4) had the same examination. The circumferential profiles of normal subjects closely resembled those of anatomical sections, with a minimum at the upper and anterior septal wall (the limit between the two areas being undefinable), a maximum at the anterolateral papillary muscle and adjacent myocardium, a minimum at the inferior wall and a maximum at the posterior papillary muscle and adjacent septum. These curves enabled us to determine the relative perfusion values of one area compared with another, which will serve as reference.(ABSTRACT TRUNCATED AT 250 WORDS)

[Abnormal origin of the left coronary artery. Pre- and postoperative hemodynamic and metabolic studies]

The authors report the case of an asymptomatic 45 year old man in whom an abnormal origin of the left coronary artery was discovered fortuitously. Coronary angiography was carried out for electrocardiographic signs of anterior myocardial infarction and showed the left coronary artery arising from the pulmonary artery: there was apical dyskinesia with alteration of global left ventricular function. The ostium of the left coronary artery was closed and a saphenous vein aorto-left anterior descending artery bypass was performed. There were no complications. Left ventricular function has not improved 8 months after surgery. The haemodynamic and coronary signs of myocardial ischaemia demonstrated preoperatively regressed after surgery: the coronary "steal" caused by the malformation which led to poor perfusion of the territory of the left coronary artery has therefore been corrected by surgery. This procedure should be carried out as early as possible in order to limit extension of the myocardial lesions.

[Intravenous labetalol in normotensive coronary patients. Effects on hemodynamics and myocardial metabolism]

The haemodynamic and myocardial metabolic effects of intravenous Labetalol were studied in 7 normotensive coronary patients with at least one significant stenosis on the left anterior descending artery. The study consisted of 5 successive observation periods: basal (I); during atrial pacing at the theoretical maximal heart rate or when anginal pain occurred (II); return to basal conditions (III); 20 minutes after an injection of 1.5 mg/kg of Labetalol over 3 minutes into the pulmonary artery (IV); during repeat atrial pacing at the rate achieved during phase II (V). There was no significant difference between phases I and III except for a slightly faster heart rate in phase III. The effects of Labetalol were assessed by comparing the results during phases III and IV between phases II and V and by analysing the variations between phases I, II, IV and V. In comparison with basal conditions (phase III), Labetalol (phase IV) induced a slight decrease in cardiac output (p less than 0.05), a decrease in aortic pressure and systemic arterial resistances (p less than 0.01) and of the double product. Coronary sinus flow did not change but myocardial oxygen consumption fell by an average of 11% (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

[Myocardial infarction with normal coronary vessels in young subjects. Apropos of 2 cases with an interval of 2 months in 2 brothers aged 32 and 34]

The authors report 2 cases of myocardial infarction with normal coronary arteries occurring at an interval of 2 months in 2 brothers aged 32 and 34. Following an episode of angina, the younger brother, a sportsman, but a smoker, developed an antero-septal infarct at rest, which was complicated by complete persistent right bundle branch block. Ventriculography and coronary angiography were normal. Induced spasm tests were not performed. The elder brother presented an infero-apico-lateral infarct on effort, without any prodromal syndrome, which was complicated by apical akinesia. Ventriculography revealed mitral prolapse. Coronary angiography was normal and the methylergometrine test was negative. In relation to this example of familial infarction with normal coronary vessels, the authors review the features of this type of infarction reported in the literature which predominantly occurs in young people. They discuss the principal points of interest, including the incidence, the criteria of definition based on the coronary angiography, the elements of the prognosis, the pathophysiological mechanisms and the possibility of a genetic predisposition.

[Acute hemodynamic and coronary effects of captopril in chronic cardiac failure]

The acute effects of captopril on haemodynamics, coronary flow and myocardial metabolism were studied in 12 patients with chronic severe cardiac failure (primary cardiomyopathy: 10 cases; ischaemic: 2 cases) in functional Classes III or IV of the NYHA. All patients were male and their average age was 51.3 +/- 14.1 years (range 27 to 68 years). Measurements were carried out under basal conditions and 90 minutes after a single dose of 50 mg (5 cases) or 100 mg (7 cases) of captopril. Captopril administration leads to an increase in cardiac index from 2.05 +/- 0.32 to 2.34 +/- 0.35 l/min/m2 (p less than 0.05) and a greater increase in systolic index from 23.9 +/- 6.7 to 29.8 +/- 6.9 ml/syst/m2 (p less than 0.01), because the heart rate decreased slightly (p less than 0.05). These changes were the result of a decrease in afterload: mean aortic pressure fell from 85 +/- 11.8 to 68 +/- 19.6 mmHg (p less than 0.01) and systemic arterial resistance fell from 2 886 +/- 745 to 2 010 +/- 610 dynes/cm-5/sec/m-2 (p less than 0.01). Captopril also led to a fall in venous tone, i.e. pre-load: left ventricular end diastolic pressure fell from 26.9 +/- 6.1 to 20.8 +/- 6.6 mmHg: p less than 0.01. There was no change in contractility as shown by the absence of variation of the V.max (0.92 +/- 0.18 under basal conditions, and 0.90 +/- 0.15 after 90 minutes).(ABSTRACT TRUNCATED AT 250 WORDS)

[Determination of the optimal dose of captopril in the treatment of severe cardiac failure by hourly hemodynamic monitoring]

The optimal dose of Captopril was evaluated by hourly haemodynamic monitoring in 10 patients with chronic congestive cardiac failure (Stage IV of the NYHA Classification) after administration of 25 mg, 50 mg, and 100 mg of Captopril. A similar improvement was observed in all the parameters considered with all three dosages. At its peak effect (90 minutes) 25 mg of Captopril caused a fall in pulmonary capillary, and mean pulmonary artery pressures, and a fall in systemic resistance of 40%, 20% and 30% respectively; with 50 mg of Captopril, the effect was a fall of 36%, 24% and 35% respectively. The cardiac index rose by 17% with 25 mg of Captopril, 28% with 50 mg and 12% with 100 mg of Captopril. Although the fall in pulmonary capillary pressure remained significant up to the 6th hour, the improvement in cardiac index was not significant after the 3rd hour. After 8 days' treatment, plasma renin activity increased from 7.01 +/- 4.68 to 23.6 +/- 18.3 ng/ml/hour (p less than 0.02) and serum aldosterone fell from 1.175 +/- 386 p. moles/l to 497 +/- 277 p. moles/l (p less than 0.001). There was no correlation between basal plasma renin activity and pre- or post-therapeutic systemic resistances. The clinical and haemodynamic improvement was sustained after 2 months' treatment in 5 of these patients without side effects. Increasing the dosage of Captopril does not reinforce or prolong its action; moderate doses (25 mg) are as effective as high doses (100 mg). Captopril, which acts by inhibiting the renin- angiotensin-aldosterone system is the current treatment of choice in severe refractory cardiac failure.

[Comparison of quantitative data from two-dimensional echocardiography and anatomical examination in mitral stenosis]

This prospective study was undertaken to assess the results of 2D echocardiography in the assessment of valvular and subvalvular lesions in mitral stenosis. The echocardiographic findings (E) were compared with peroperative and laboratory anatomical examination of the excised valve (A). The following criteria were compared: 1) planimetry of mitral valve surface area, 2) mobility of the anterior leaflet, assessed anatomically by the flexibility of the tissue, and echocardiographically by the amplitude of early diastolic excursion, 3) length of anterior and posterior leaflets, 4) presence of calcification, 5) length of the longest tendinae chordae, measured from the papillary muscle to the insertion of the valve, 6) thickness of the thickest tendinae chordae attached to each leaflet. Echocardiography was carried out preoperatively by two different operators without knowledge of the haemodynamic and later anatomical findings. The anatomical results were taken as reference. Mitral valve surface area measured by both methods was comparable (A = 0,96 +/- 0,28 cm2; E = 1,04 +/- 0,33 cm2, N = 17, t = NS) and a good correlation was found between the two measurements (r = 0,79; p less than 0,01). 2D echo assessed the loss of valvular mobility by limitation of early diastolic opening of the AML with a sensitivity of 71 p. 100 and a specificity of 70 p. 100. Measurement of valve length of the anterior (N = 14) and posterior leaflets (N = 15) may be difficult in the presence of severe calcification. The results of both measurements were comparable. AML, 25,2 +/- 1,9 mm (A) and 24,6 +/- 2,1 mm (E); PML, 13,9 +/- 1,9 mm (A) and 14,2 +/- 2,2 (E) correlated well, r = 0,71 and r = 0,71 respectively (p less than 0,01).(ABSTRACT TRUNCATED AT 400 WORDS)

[Recurrent ejection of aortic valve prostheses. Apropos of 22 case reports]

Twenty two cases of recurrent perivalvular leaks in aortic valve prostheses were reviewed in a multicentre cooperative study. From 1963 to 1978, 22 patients, mean age 39 years, underwent aortic valve replacement; 18 patients had aortic regurgitation, 6 due to infective endocarditis, and 4 patients had calcific aortic stenosis. Eight Starr-Edwards, 6 Smeloff-Cutter, 2 Braunwald-Cutter, 3 Björk, 1 Lillehei-Kaster and 2 bioprostheses were inserted. All 22 patients had to be reoperated for perivalvular leaks due to active or previous infective endocarditis in 7 cases. The prostheses implanted (3 reinsertions, 19 valve replacements) were 10 Starr-Edwards, 4 Smeloff-Cutter, 5 Björk, 1 Lillehei-Kaster, 1 Magovern and 1 bioprosthesis. All 22 patients had further perivalvular leaks, 6 caused by infective endocarditis, and 15 patients underwent a third operation. The prostheses implanted this time (2 reinsertions, 13 valve replacements) were 4 Starr-Edwards, 3 Smeloff-Cutter, 7 Björk and 1 bioprosthesis. Four patients had a third perivalvular leak, and 2 patients a fourth perivalvular leak. The first and second episodes of perivalvular leak were detected early in over half the cases. They were associated with cardiac failure, angina and hemolysis in 20 to 45% of cases. The average period between the first and second operations, and the 2nd and 3rd operations were 15 months and 9 months respectively. Overall, 11 patients died (50%), 4 due to cardiac failure and 3 of sudden death; 3 patients have been lost to follow-up (14%), and there are 8 survivors (36%) with a mean follow-up period of 5 years. However, the mortality rate when the cause of perivalvular leak was infective, was 82%, and only 18% when the cause was mechanical. The factors which favour recurrent perivalvular leaks are infection (30% of cases) and technical difficulties related to the poor quality of the aortic ring (calcification, dystrophy or dilatation). The prevention of this complication depends on careful peroperative technique, the use of certain surgical bypass techniques, a constant battle against infection, and regular examination of operated patients.

[Mitral incompetence as presenting feature of idiopathic left ventricular aneurysm (author's transl)]

A further case of the exceptionally rare condition of idiopathic left ventricular aneurysm is reported in which the lesion was detected in a most unusual manner. The patient, a young 22-year-old negro woman, had been admitted for investigation of a mitral incompetence. The true diagnosis was established by angiography, which demonstrated a large multilobular left ventricular aneurysm, also communicating with the left auricle, this being the cause of the mitral incompetence. Surgical correction of the lesion suppressed the mitral leak without touching the normal mitral apparatus.