Frederic Bouvier

Comparison of Different Echocardiographic Methods With Radionuclide Imaging for Measuring Left Ventricular Ejection Fraction During Acute Myocardial Infarction Treated by Thrombolytic Therapy

The aim of this study was to: (1) compare the usefulness, in clinical practice, of different echocardiographic methods of left ventricular (LV) function determination in patients with a recent thrombolytic-treated acute myocardial infarction (AMI); (2) compare these measurements with the reference method radionuclide imaging; and (3) evaluate the reproducibility of visual estimation of the LV ejection fraction (EF) and the use of the biplane method of discs (Simpsons rule) in clinical practice. Echocardiography and radionuclide imaging were performed within 2 hours of each another, 5 to 8 days after hospital admission. Ninety-six patients (70 men and 26 women) age 64 +/- 9 years (range 45 to 75) were studied. The echocardiographic study was performed by 2 experienced physicians, independently of each another. LV wall motion score index and visual estimation of the EF correlated best with the radionuclide EF (r = 0.72 and r = 0.71), thereafter simply counting the number of affected LV segments (r = 0.67) or atrioventricular plane measurements (r = 0.64). Simpsons rule had low correlation to the radionuclide EF (r = 0.45 to 0.51) and could not be used in approximately half of the patients due to poor identification of endocardial borders. The interobserver coefficient of variation for independent visual echocardiographic estimation of the EF was 10%, for Simpsons rule 18%, and for the radionuclide EF 5%. We conclude that the EF estimated from quantitative echocardiographic volume calculations (Simpsons rule) may differ substantially from radionuclide methods of measuring the EF. However, with experienced sonographers, the LV wall motion score index or visual estimation of the EF had reasonable agreement with the radionuclide EF in most of the patients. Atrioventricular plane measurement is an acceptable alternative.

Left ventricular function and perfusion in elderly endurance athletes.

PURPOSE To study the extent to which lifelong physical training can affect cardiovascular capacity, left ventricular function, and myocardial perfusion in elderly men. METHODS AND RESULTS Ten healthy male veteran endurance athletes aged 73 +/- 3 yr (mean +/- SD) and a control group of 12 sedentary or moderately physically active healthy subjects aged 75 +/- 2 yr were studied. Echocardiographic examinations at rest and exercise stress tests were performed. Gated blood pool scans and myocardial perfusion scintigraphy were recorded at rest and during exercise. Maximal VO2 was 41 +/- 7 mL.kg-1.min-1 in the athletes and 26 +/- 5 mL.kg-1.min-1 in the controls (P < 0.001). Echocardiographic measures of systolic and diastolic function at rest were better in the athletes. The ejection fraction during exercise was also higher in the athletes (P = 0.003). Seven of the 10 athletes, but none of the controls, had pathological myocardial perfusion findings. CONCLUSIONS By endurance training, a high level of physical capacity can be maintained late in life. The superior cardiovascular function in the veteran athletes, compared with the untrained controls was due to both better systolic and diastolic left ventricular function. Myocardial perfusion defects in athletes should be judged with caution, as this finding is common both in veteran athletes and as previously shown, in young athletes.

Risk assessment in patients with acute myocardial infarction treated with thrombolytic therapy

Abstract. Jensen‐Urstad M, Samad BA, Jensen‐Urstad K, Hulting J, Ruiz H, Bouvier F, Höjer J (Karolinska Hospital, Karolinska Institute, Stockholm; Söder Hospital, Karolinska Institute, Stockholm; Karolinska Hospital, Karolinska Institute, Stockholm; and Söder Hospital, Karolinska Institute, Stockholm, Sweden). Risk assessment in patients with acute myocardial infarction treated with thrombolytic therapy. J Intern Med 2001; 249: 527–537.

Delayed recovery of myocardial perfusion in acute myocardial infarction: a scintigraphic study after early thrombolytic treatment.

BACKGROUND: Assessments of compromised myocardium and infarct size early after thrombolytic treatment in acute myocardial infarction (AMI) are important for risk stratification and for treatment management. We have therefore evaluated the clinical usefulness of myocardial perfusion scintigraphy (MIBI-SPECT) for the assessment of myocardial viability early after AMI. METHODS: Seventy-one patients [53 men and 18 women, aged 64 +/- 9 years (range 45-75 years)] with AMI treated by thrombolysis took part in this prospective study at University Hospital, Stockholm, Sweden. Sixty of them underwent adenosine-stress and resting MIBI-SPECT 2-4 days after AMI, and 11 were examined only at rest. Six months after the AMI, a repeat MIBI-SPECT at rest was obtained for comparison. RESULTS: All patients had significant perfusion defects compared with an age- and sex-matched healthy reference population. Seventy-six percent of the patients able to undergo a complete adenosine-stress and rest SPECT showed signs of reversible perfusion defects. Defect size (extent) and severity at rest decreased between the tests at 2-5 days and 6 months after AMI (P < 0.001). Reversible perfusion defects early after AMI were not related to spontaneous improvement of myocardial perfusion 6 months later. Early, semiquantitative MIBI-SPECT was not able to predict final infarct size as measured by resting perfusion data 6 months after AMI, regardless of whether the threshold value was set at 30, 40, 50 or 60% of the maximal isotope uptake in the early resting scan. CONCLUSIONS: Myocardial perfusion scintigraphy with adenosine-stress and resting MIBI-SPECT early after AMI underestimates myocardial viability in the majority of patients treated with thrombolytic agents. Neither reversible perfusion defects nor regional semi-quantitative perfusion data appear to predict spontaneous improvement of perfusion 6 months after AMI.

Myocardium at risk with contrast enhanced SSFP compared to myocardial perfusion SPECT

Methods Sixteen patients with STEMI (age 64 ± 8 years) received intravenous 99 m-Tc immediately before primary percutaneous coronary intervention. A SPECT investigation was performed within four hours. MaR was defined as the non-perfused myocardial volume on SPECT. Magnetic resonance imaging (MRI) was performed 7.8 ± 1.2 days after the myocardial infarction using a protocol in which the contrast agent was administered before acquisition of short-axis cine images. MaR was evaluated as the contrast enhanced myocardial volume in cine SSFP by two blinded observers. Results MaR determined from the enhanced region on cine SSFP correlated significantly with that derived with SPECT (r2 = 0.78, p < 0.001). The difference in MaR determined by MRI and SPECT was 0.5 ± 5.1% (mean ± SD). The interobserver variability of contrast enhanced cine SSFP measurements was 1.6 ± 3.7% (mean ± SD) of the left ventricle wall volume Figures 1 and 2.