Lipoproteins in heart transplantation: proton magnetic resonance spectroscopy of plasma

Despite the major improvement in immunosuppressive therapy, noninvasive detection of heart graft rejection remains a challenge. As lipoproteins are involved in several immunomodulation mechanisms, we studied their proton NMR spectra in plasma from patients after heart transplantation. NMR data were compared to clinical and functional evaluation of rejection process. The total linewidth (TLW) of methyl and methylene peaks, mainly arising from lipoproteins, were significantly lower for patients without a rejection process than for patients before surgery and patients with evidences of a rejection process. When TLW values are referred to TLW on the 8th day for each patient, the sensitivity and the specificity of the test are increased, with resulting positive and negative predictive values of 90 and 91%, respectively. The results obtained on more than 400 samples from 46 patients justify the use of proton NMR spectroscopy as a clinical tool.

[Noninvasive evaluation of partial beta adrenergic agonist properties of xamoterol in cardiac insufficiency]

The effects of an intravenous injection of 0.15 mg/Kg of xamoterol were studied non-invasively under basal conditions and during beta-1-adrenergic stimulation with dobutamine in 16 patients with dilated cardiomyopathy and severe cardiac failure. Xamoterol did not cause any detectable agonist effect but was well tolerated under basal conditions. Its potential antagonist effect was only detected during the dobutamine infusion: xamoterol significantly reduced the increase in heart rate (p less than 0.001), the systolic blood pressure (p less than 0.01), the rate-pressure product (p less than 0.001) and the cardiac index (p less than 0.001) produced by the administration of dobutamine.

Altered sarcoplasmic reticulum Ca2(+)-ATPase gene expression in the human ventricle during end-stage heart failure

A decrease in the myocardial level of the mRNA encoding the Ca2(+)-ATPase of the sarcoplasmic reticulum (SR) has been recently reported during experimental cardiac hypertrophy and failure. To determine if such a deficit occurs in human end-stage heart failure, we compared the SR Ca2(+)-ATPase mRNA levels in left (LV) and right ventricular (RV) specimens from 13 patients undergoing cardiac transplantation (6 idiopathic dilated cardiomyopathies; 4 coronary artery diseases with myocardial infarctions; 3 diverse etiologies) with control heart samples using a rat cardiac SR Ca2(+)-ATPase cDNA probe. We observed a marked decrease in the mRNA for the Ca2(+)-ATPase relative to both the 18S ribosomal RNA and the myosin heavy chain mRNA in LV specimens of patients with heart failure compared to controls (-48%, P less than 0.01 and -47%, P less than 0.05, respectively). The LV ratio of Ca2(+)-ATPase mRNA to 18S RNA positively correlated with cardiac index (P less than 0.02). The RV ratio correlated negatively with systolic, diastolic and mean pulmonary arterial pressures (P less than 0.02, P less than 0.02, and P less than 0.01, respectively). We suggest that a decrease of the SR Ca2(+)-ATPase mRNA in the myocardium plays an important role in alterations of Ca2+ movements and myocardial relaxation reported during human end-stage heart failure.

[Evolution of the primary successes of percutaneous aortic valvuloplasty]

Between November 1985 and August 1988, we performed 89 percutaneous aortic valvuloplasties. Sixty-two of these were considered a primary success on the basis of two main criteria: stage I or II on discharge and greater than 50 p. 100 increase in aortic valve area. The mean age of these patients was 78.4 +/- 6.1 years. On actuarial analysis, after 5 months 98 p. 100 of the patients with primary success were alive and 89 p. 100 were in stage I or II and had not been operated upon or redilated. At 15 months 79 p. 100 of the patients with primary success were alive, but only 48 p. 100 were in stage I or II and neither operated upon or redilated. Ultrasonic data obtained one and twelve months after dilatation were compared in 8 patients who had kept the full functional benefit of angioplasty for 14.6 +/- 4.3 months (group 1) and 9 patients who had lost this initial benefit (group 2). In group 1 patients the aortic valve area had moderately and non significantly diminished from 0.92 to 0.72 cm2. In group 2 patients the aortic valve area had gone down from 0.89 to 0.63 cm2 (p less than 0.01), indicating restenosis. We conclude that after the 4th post-valvuloplasty month the medium-term success of the procedure undergoes some degradation, and in these patients the echocardiographic signs of stenosis are clear-cut.

[Heart transplant. Long-term follow-up]

The use of cyclosporin in the immuno-suppressive treatment has resulted in a spectacular improvement of the outcome of cardiac transplantation. But a number of complications, if they have become less severe, have note however totally disappeared. In order to detect them at an early stage, a strict monitoring is necessary. Systematic ambulatory visit are organized in the transplant center. In the interval between visits, a medical follow-up by cardiologist and attending physician is absolutely necessary.

[Prevalence of patent foramen ovale in young patients with ischemic cerebral complications]

We compared the prevalence of patent foramen ovale (PFO), detected by two-dimensional contrast echocardiography, in a group of 60 adults aged under 55 who had experienced a cerebral ischaemic accident and had normal standard examination of the heart, and in a control group of 100 patients. The prevalence of PFO was significantly higher in neurological patients (40 p. 100) than in controls (10 p. 100; p less than 0.001). Within the neurological group, the prevalence of PFO determined blindly, i.e. without any knowledge of the aetiological diagnosis, increased with the uncertainty of diagnosis: 21 p. 100 when a cause could be determined (n = 19), 40 p. 100 when a facilitating factor of cerebral accident, such as mitral valve prolapse, migraine or consumption of oral contraceptives, could be identified (n = 15), and 54 p. 100 when neither cause nor facilitating factor could be found (n = 26; p less than 0.10). In view of the very high prevalence of clinically silent venous thrombosis, these results suggest that paradoxical embolism through a PFO might be responsible for cerebral ischaemic accidents more frequently than is generally believed.

[Echocardiographic detection of adriamycin cardiotoxicity. Study of the relationship between the shortening fraction-constraint and the systolic shortening fraction-diameter of the left ventricle]

Cardiotoxicity is the main obstacle to the use of high-dosage adriamycin in chemotherapy. It is difficult to decide whether or not treatment should be continued when the cardiac function -- irrespective of the method by which it is evaluated -- is at the lower limit of normality. Some authors consider that chemotherapy can be pursued as long as the shortening fraction of the echocardiographic diameter remains within normal limits in relation to the end-systolic constraint. We have established the limits of normality of this relationship before chemotherapy in 53 patients with normal cardiovascular system. We conclude that the end-systolic constraint essentially depends on the end-systolic diameter, so that the results provided by the study of the shortening fraction end-systolic constraint relationship are qualitatively the same as those of the shortening fraction-end-systolic diameter relationship, which is much easier to obtain. It seems to us that the criteria of cardiotoxicity after administration of adriamycin 300 mg/m2 are: (1) shortening fraction lower than 25 p. 100; (2) ventricular dilatation (end-systolic diameter greater than 40 mm) without associated valve disease; (3) reduction of the shortening fraction (whatever its value) in relation to the end-systolic diameter by more than 2 standard deviations on the regression slope of the correlation; (4) more than 25 p. 100 reduction of the shortening fraction after administration of adriamycin 300 mg/m2, betraying a high sensitivity to the cardiotoxic effects of the drug. Such individual sensitivity, studied in 25 patients, seemed to vary widely from one subject to another and to be independent of the initial status.(ABSTRACT TRUNCATED AT 250 WORDS)

[Doppler ultrasound evaluation of aortic insufficiency using half-pressure time. Absence of arterial rigidity influence]

In 20 patients with pure aortic regurgitation we studied the relationship between the severity of regurgitation, as assessed haemodynamically by the percentage of leakage (%L), and the half-pressure (T 1/2 P) and half-velocity (T 1/2 V) times, as obtained from doppler aortic blood velocity curves, taking into account the rigidity of the systemic vascular circuit characterized by the pressure wave propagation velocity (PWPV). The systemic arterial circuit was supple in 14 patients (PWPV less than 7.5 m/sec) and rigid in 6 patients (PWPV greater than 7.5 m/sec). The regression slopes between %L and T 1/2 P and between %L and T 1/2 V were calculated with their confidence limits in the 14 patients with supple arteries. The 6 patients with rigid arteries fitted into this nomogram, thus demonstrating that systemic arterial rigidity makes no difference in the relationship between %L and doppler indices. The half-velocity and half-pressure times measured by doppler ultrasound were acquired from a velocity signal directly determined by the aortic regurgitation, without any detectable effect of vascular circuit rigidity. Being equivalent by nature to the signal decrease time constant, they are independent of the absolute protodiastolic value of diastolic pressure gradient or blood flow velocity. For this reason these two doppler parameters are reliable to evaluate the severity of aortic regurgitation.

[Course of aortic valve insufficiency in percutaneous aortic valvuloplasty]

The risk of occurrence or aggravation of aortic valve regurgitation after percutaneous aortic valvuloplasty was evaluated by angiography in 50 consecutive patients: 17 men, 33 women, mean age 77.6 years. In all cases angiography was performed with a pigtail catheter, trying to get the catheter in the same position for injections before and after dilatation. Forty-one patients showed no changes from the predilatation situation: aortic regurgitation was absent in 10 cases, minimal in 30 cases and moderate in 1 case. Minute leakage developed in a patient who had no aortic valve regurgitation prior to dilatation. Regurgitation decreased or subsided in 8 patients, i.e.: moderate leakage became minimal in 6 cases and minimal leakage completely disappeared in 2 cases. In the last 8 patients (3 men, 5 women, mean age 76 years) heart rate and transaortic diastolic pressure gradient were identical before and after dilatation, which means that the angiographic reduction of leakage was due to better closure of the valve. Aortic valve dilatation seems to carry a low risk of major aortic regurgitation. In patients who require percutaneous valvuloplasty for tight aortic valve stenosis, the presence of a small or moderate aortic leakage should not preclude the procedure from being performed.

[Reproducibility of myocardial ischemia induced by atrial stimulation]

Reproducibility of myocardial ischemia induced by atrial pacing (P) was investigated in 25 patients (pts) without previous anterior myocardial infarction and showing a positive exercise stress test. The second period of atrial pacing (P2) was exerted 20 minutes after the first (P1). During P2, a reduction in the parameters reflecting myocardial oxygen requirements (maximal left ventricular pressure, dp/dt max, TTI*HR values) was noted, while the signs of ischemia were less pronounced (ST depression decreasing from 2.3 +/- 1 mm to 1.6 +/- 1.0 mm; % of lactate extraction (%L) decreasing from - 6.4 +/- 25.5 to + 8.5 +/- 19.2; p less than 0.5). The 25 pts were divided into 2 groups according to the ejection fraction (EF greater than .55 16 pts Gr.F+; EF less than .55 9 pts Gr.F-). The distribution of coronary lesions was the same for the 2 groups. During P1 GR.F+ registered a negative % L as opposed to Gr.F-. During P2, the difference in the % L between the 2 groups was also significant (2.6 +/- 19.9% F+ vs 18.9 +/- 14.3% F-; p less than .05). Collateral circulation had no effect upon the results, neither for P1 or P2. This study shows that a second period of atrial pacing, 20 minutes after the first, induced lesser ischemia than the first period of atrial pacing. This phenomenon could explain the paradoxical improvement observed in certain patients after a first episode of angina. These results have implications as regards the necessity of double blind studies compared to placebo when using this technique in the evaluation of the effects of anti-ischemic drugs.