17-iodoheptadecanoic-acid and Myocardial-Infarction

The results described in the literature of myocardial scintigraphy with radioiodinated heptadecanoic acid (IHDA) to detect coronary stenoses are contradictory. In the present study, IHDA scintigraphy was performed in nine control subjects and 67 patients with coronary artery disease. The acquisition time was 75 min and background correction was not applied. The time-activity curves of regions of interest were analyzed by curve fitting with a monoexponential plus constant. Two parameters were used: the halftime value of the monoexponential (T1/2 in min) and the ratio of the amplitude (A) of the monoexponential and the total activity at time t = 0 (amplitude + constant = A + C): A/A + C as a percentage. Based on the control group, a region of normal T1/2 values and A/A + C ratios was defined, for each calculated T1/2-A/A + C pair the probability of originating from a normal region was calculated. The value of the IHDA test, using the index of merit (sensitivity + specificity-100%), increased in the patient group without MI with the severity of the stenosis (21%, 24% and 47% for stenoses greater than or equal to 75%, greater than or equal to 90% and greater than or equal to 99%). In patients with MI, only small positive values in regions of non-infarct-related vessels were found (-1%-16%). It is concluded that the value of the IHDA test to detect stenoses of coronary arteries is too low to apply this test in clinical practice. However, a new type of analysis is offered, based on curve fitting of individual pixels.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Angina Pectoris; Fatty Acids; Humans; Iodine Radioisotopes; Myocardial Infarction; Myocardium; Radionuclide Imaging

This trial aimed to test if the half life of radioiodinated heptadecanoic acid (HDA) in acutely infarcted myocardium is of prognostic value. Twenty patients had an HDA scan and a MUGA scan within 6 days of acute myocardial infarction, eighteen of these had a visible defect on the HDA images. The mean half life of the areas of acute infarction (15.50 min +/- 7.82 min) was significantly shorter than that of normal myocardium (20.77 min +/- 4.00 min). The MUGA scan was repeated after 6 months in 15 patients. The mean acute infarct half life was longer in patients with an LVEF improvement of at least 5% at 6 months (16.92 min +/- 10.56 min), compared to those with a deterioration of more than 5% (11.75 min +/- 4.03 min), although the difference is not statistically significant. While the results in a few individuals suggested that the half life may be of prognostic significance, the variable response of the group reduced the ability of the half life to act as a prognostic indicator. Improvements in imaging and background subtraction techniques may be necessary before the half life is of practical value.

Topics: Clinical Trials as Topic; Fatty Acids; Half-Life; Humans; Iodine Radioisotopes; Myocardial Infarction; Prognosis; Radionuclide Imaging

On the basis of the results which we obtained having performed 25 examinations on 15 patients with angina pectoris syndrome, myocardial infarctions and condition after bypass operation the preparation 123I hepatadecanoic acid produced in the Central Institute for Nuclear Research Rossendorf is very well suited for the scintigraphic demonstration of the myocardium. Moreover it is possible to recognize selectively diagnostically interesting regions with different radioactivity intake, retention and elimination of the radiopharmacon pharmacon and with the help of quantitative parameters to characterize concerning the metabolic efficiency. We consider the 123I hepatadecanoic acid suitable for the clinical use in establishing the global and regional metabolic efficiency of the myocardium. It is very well to be used for the primary diagnostics and represents an evident diagnostic remedy for the assessment of the course of myocardial diseases and the success of therapy.

Topics: Adult; Aged; Angina Pectoris; Cardiac Output; Coronary Artery Bypass; Fatty Acids; Humans; Middle Aged; Myocardial Contraction; Myocardial Infarction; Postoperative Complications; Radionuclide Imaging

Twenty-three patients with successful intracoronary thrombolytic therapy in the acute stage of infarction underwent scintigraphy with radioiodinated heptadecanoic acid two weeks after myocardial infarction and three to 12 months later. In patients with normal or slow elimination rates in the infarct area, ejection fractions were significantly higher than in patients with fast elimination (70 +/- 6% vs 47 +/- 13%, P less than 0.05). Consequently, left ventricular damage score was lower in patients with normal and slow elimination rates (1.7 +/- 1.6 vs 4.9 +/- 2.4, P less than 0.05). Repeated scintigraphy showed normalization of the elimination rates in patients with previously slow elimination, except in one patient in whom the elimination rate remained slow, patients with fast elimination rates remained unaltered. It is concluded that scintigraphy with radioiodinated heptadecanoic acid is an appropriate method to assess myocardial viability in patients with successful thrombolytic therapy.

Topics: Adult; Aged; Fatty Acids; Fatty Acids, Nonesterified; Fibrinolytic Agents; Humans; Middle Aged; Myocardial Infarction; Radionuclide Imaging; Stroke Volume

I-123-omega-heptadecanoic acid (HDA) was evaluated for myocardial scanning in 59 healthy volunteers and 133 patients, using a 7-pinhole collimator. Early (uptake) and late (retention) images were compared visually. Regional HDA elimination was also followed semiquantitatively based on the calculation of a retention-over-uptake ratio, R(phi), derived from the maximal counts/pixel in 60 midventricular slice sectors. The healthy heart concentrated HDA homogeneously in all segments with no difference between early and late images. The minimal R(phi), taken as representative of that myocardium with the best function, was unchanged after maximal ergometer stress and with dipyramidole-induced hyperperfusion. A circumscribed decreased HDA uptake is the clear-cut criterion for an abnormal finding. HDA tomography of the myocardium had an 86% sensitivity for myocardial infarcts (MIs) up to 4 wk old, and 83% for myocardial scars (MSs). Comparing early and late tomograms, we find a cool-warm sequence more often with acute and subacute MIs. A cool-cool or a cold-cold sequence dominated with MSs. HDA tomoscintigraphy cannot replace TI-201 for the evaluation of regional coronary reserve in coronary heart disease.

Topics: Adult; Aged; Coronary Disease; Evaluation Studies as Topic; Fatty Acids; Female; Heart; Humans; Iodine Radioisotopes; Male; Middle Aged; Myocardial Infarction; Myocardium; Radioisotopes; Radionuclide Imaging; Thallium; Tomography

We have already shown that myocardial imaging properties of radio-iodinated long-chain free fatty acids (123I-FFA) and thallium 201 (201TI) are comparable in detecting areas of inadequate myocardial perfusion (van der Wall et al. 1980). Besides confirming our earlier observations, the present study tests the potential of 123I-FFA, hexadecenoic acid (123I-16-ha), and heptadecanoic acid (123I-17-H degree A), in assessing regional myocardial metabolism in 30 patients within a week of proven myocardial infarction. The clearance rates (t1/2) of FFA were estimated from mono-exponential time-activity curves, obtained by external detection over infarcted and normally perfused areas during a 30-min period after IV administration of 3-5 mCi 123I-16-HA or 123I-17-H degree A. Six normal subjects served as controls. The t1/2 values in the infarcted areas were found to be significantly lower (18.5 +/- 2.1 min; mean +/- SD, with 123I-16-HA and 16.8 +/- 3.5 min with 123I-17-H degree A) than in non-infarcted areas (34.0 +/- 8.4 min with 123I-16-HA and 34.8 +/- 7.7 with 123I-17-H degree A). The t1/2 values in the control group (27.5 +/- 3.0 min with 123I-17-H degree A) were not significantly different from values found in non-infacted areas in the patient group. Our findings of faster FFA turn-over rates in infarcted tissue are in contrast to previous studies, which have shown prolonged turn-over rates in reversibly ischaemic myocardiu. We conclude that the study of turn-over rates of FFA provides a means to distinguish normally perfused, reversibly ischaemic and irreversibly ischaemic myocardium.

Topics: Adult; Aged; Coronary Angiography; Fatty Acids; Fatty Acids, Nonesterified; Female; Heart; Humans; Iodides; Iodine Radioisotopes; Male; Middle Aged; Myocardial Infarction; Myocardium; Palmitic Acids; Radionuclide Imaging