Marco Mazzanti

Diagnostic Criteria and Management of Subacute Ventricular Free Wall Rupture Complicating Acute Myocardial Infarction

In this prospective study we evaluated the value of the main diagnostic criteria for postinfarction subacute rupture of the ventricular free wall. Two-dimensional echocardiograms and recordings of right atrial pressure and waveform were immediately obtained in every patient exhibiting rapid clinical and/or hemodynamic compromise in the acute infarction setting. The same protocol was applied to patients referred from other hospitals for suspected myocardial rupture. In 28 cases a subacute free wall rupture was identified. In most of the patients the diagnosis was based on the demonstration of hemopericardium and cardiac tamponade by echocardiography, cardiac catheterization and, occasionally, by pericardiocentesis. In 2 instances, the identification of intrapericardial echo densities suggesting clots, in the absence of cardiac tamponade, allowed a diagnosis of subacute rupture. Direct, but indistinct visualization of myocardial rupture was obtained in 4 cases. Among the 28 patients with this complication, 4 died while awaiting surgery and 24 underwent surgical repair (mortality rate 33%). Long-term outcome of survivors was favorable. Various myocardial lesions underlie postinfarction subacute free wall rupture. Clinical presentation varied widely. The diagnosis was based, usually but not always, on the association of hemopericardium and signs of cardiac tamponade. An organized approach to management of this complication of acute myocardial infarction was suggested.

Feasibility and Diagnostic Accuracy of a Gated SPECT Early-Imaging Protocol: A Multicenter Study of the Myoview Imaging Optimization Group

The aim of this study was to investigate whether early (time 1, or T1) myocardial tetrofosmin imaging is feasible and as accurate in detecting coronary artery disease as is standard delayed (time 2, or T2) imaging. Methods: One hundred twenty patients (100 men and 20 women; mean age ± SD, 61 ± 10 y) with anginal symptoms underwent tetrofosmin gated SPECT. Stress/rest T1 imaging was performed at 15 min and T2 at 45 min after injection. Image quality was visually evaluated using a 4-point scale (from 0 = poor to 3 = optimal). Myocardial perfusion analysis was performed on a 20-segment model using quantitative perfusion SPECT software, and reversible ischemia was scored as a summed difference score (SDS). Coronary angiography was performed within 1 mo on all patients, and stenosis of more than 50% of the diameter was considered significant. Results: Overall, quality was scored as optimal or good for 94% of T1 images and 95% of T2 images (P = not statistically significant). Heart, lung, liver, and subdiaphragmatic counts did not differ for stress and rest T1 and T2 imaging. A good linear relationship was seen between T1 and T2 SDS (r = 0.69; P < 0.0001), and Bland–Altman analysis showed good agreement between the 2 conditions. In terms of global diagnostic accuracy, areas under the receiver-operating-characteristic curve were comparable between T1 and T2 (0.80 vs. 0.81, P = not statistically significant). Discrepancies between T1 and T2 SDS were observed in 44% of patients (T1 − T2 SDS > 2). Linear regression analysis showed a good correlation between T1 and T2 SDS (r = 0.67; P < 0.0001), whereas the Bland–Altman method showed a shift in the mean value of the difference of +2.67 ± 2.73. In patients with a T1 − T2 SDS of more than 2, areas under the receiver-operating-characteristic curves were significantly higher for T1 than for T2 images (0.79 vs. 0.70, P < 0.001). Conclusion: T1 imaging is feasible and as accurate as T2 imaging in identifying coronary artery disease. However, in a discrete subset of patients, early acquisition strengthens the clinical message of defect reversibility by permitting earlier, more accurate identification of more severe myocardial ischemia.

Effects of trimetazidine on myocardial perfusion and left ventricular systolic function in type 2 diabetic patients with ischemic cardiomyopathy.

Aims: To determine whether short-term treatment with trimetazidine (TMZ), an antiischemic agent that directly inhibits fatty acid oxidation and results in stimulation of glucose oxidation, may improve myocardial perfusion and left ventricular systolic function in diabetic patients with ischemic cardiomyopathy. Methods and Results: We studied 34 clinically stable patients with type 2 diabetes mellitus (DM) and documented multivessel coronary artery disease (29 men and 5 women, mean age 54 ± 9 years) with depressed systolic function (left ventricular ejection fraction 38 ± 6%). Patients were randomized into two groups. One group received TMZ (20 mg tid) for 3 months (n = 19), while another group received a placebo during the same period (n = 15). On study entry and at 3 months, all patients underwent a gated Single Photon Emission Computed Tomography (SPECT) myocardial scintigraphy with a 2-day stress(Bruce)-rest protocol (500 MBq tetrofosmin). At 3 months, TMZ-treated patients had a significant improvement in systolic wall thickening (P < 0.05) and ejection fraction (P = 0.007) as compared with control patients. These effects were more marked in patients with more severe reversible perfusion defects on initial evaluation and were not associated with changes in myocardial defects (P = 0.38). Total exercise time was also improved in TMZ-treated patients (20.5%, P < 0.05 vs. controls). Conclusions: In diabetic cardiomyopathy, short-term TMZ improved left ventricular systolic function and functional capacity despite no change in myocardial perfusion. These benefits were more evident in patients with more severe perfusion defects on initial evaluation, suggesting that chronic myocardial ischemia is a requirement for the effects of TMZ on left ventricular systolic performance.

Fast technetium 99m-labeled sestamibi gated single-photon emission computed tomography for evaluation of myocardial function.

BackgroundThis study assesses the feasibility of 99mTc-labeled sestamibi electrocardiographic gated single-photon emission computed tomography (SPECT) with a short acquisition time (6.7 minutes, “fast” gated SPECT) for the evaluation of stress myocardial perfusion and poststress myocardial function. Simultaneous assessment of stress perfusion and poststress function is possible with standard gated SPECT acquisition (19.3 minutes) of stress-injected sestamibi. Sestamibi gated SPECT can be used to evaluate regional wall motion (RWM), thickening, and left ventricular ejection fraction (LVEF); the feasibility of fast gated SPECT has not been evaluated previously.Methods and ResultsFifty patients were studied who underwent treadmill exercise, sestamibi injection (25 to 30 mCi), and standard gated SPECT 15 minutes after exercise, immediately followed by fast gated SPECT. All patients underwent rest 201TI SPECT before exercise testing. All studies were analyzed by semiquantitative visual scoring. Both standard and fast gated SPECT were read for stress perfusion and poststress wall motion and thickening, dividing the left ventricle into 20 segments, on a 5-point scale described previously. The measurement of LVEF used a previously described automatic algorithm. Average myocardial counts per pixel were 58±19 for standard gated SPECT and 13±4 for fast gated SPECT (p=0.0001). Heart/lung ratio was 10.2±4.8 for regular gated SPECT and 10.3±5.7 for fast gated SPECT (difference not significant). Perfusion analysis showed exact agreement in 92% of the segments (κ=0.76; p<0.01). Correlation between LVEFs measured from standard and fast gated SPECT was 0.94. Analysis of 998 segments (two segments were uninterpretable) showed exact agreement in 96% (κ=0.89; p<0.001) for RWM and 94% (κ=0.83; p<0.001) for thickening between standard and fast gated SPECT. In 225 segments with abnormal RWM and 189 segments with abnormal thickening by both standard and fast gated SPECT, exact agreements were 0.92 for RWM (κ=0.90; p<0.001), and 0.87 for thickening (κ=0.80; p<0.01).ConclusionsOur data demonstrate that fast sestamibi gated SPECT is feasible and yields results equivalent to those of standard sestamibi gated SPECT with respect to left ventricular regional and global function.

Lessons learned from MPI and physiologic testing in randomized trials of stable ischemic heart disease: COURAGE, BARI 2D, FAME, and ISCHEMIA

There is a preponderance of evidence that, in the setting of an acute coronary syndrome, an invasive approach using coronary revascularization has a morbidity and mortality benefit. However, recent stable ischemic heart disease (SIHD) randomized clinical trials testing whether the addition of coronary revascularization to guideline-directed medical therapy (GDMT) reduces death or major cardiovascular events have been negative. Based on the evidence from these trials, the primary role of GDMT as a front line medical management approach has been clearly defined in the recent SIHD clinical practice guideline; the role of prompt revascularization is less precisely defined. Based on data from observational studies, it has been hypothesized that there is a level of ischemia above which a revascularization strategy might result in benefit regarding cardiovascular events. However, eligibility for recent negative trials in SIHD has mandated at most minimal standards for ischemia. An ongoing randomized trial evaluating the effectiveness of randomization of patients to coronary angiography and revascularization as compared to no coronary angiography and GDMT in patients with moderate-severe ischemia will formally test this hypothesis. The current review will highlight the available evidence including a review of the published and ongoing SIHD trials.

Gated-spect imaging using vasodilating stressor for risk stratification of subjects with or without coronary artery disease

Abstract Dipiridamole stress myocardial SPECT is known to be able to stratify the risk of cardiovascular disease, but there are not data about the additional value of post-stress and rest left ventricular ejection fraction (LVEF), by gated-SPECT (gS) analysis, in the same exam. Aim of our study was to evaluate the stratification of risk matching parameters of perfusion and LV function using stress-dipyridamole/rest gS. Methods: 1008 consecutive patients (pts) (715 males, mean age 69 years) performed stress-dipyridamole Tc-99 tetrofosmin gS (0.56 mg/Kg of dypiridamole in 4 minutes). For the imaging study we adopted a dual-day stress/rest protocol. Both post-exercise and resting images were gated and acquired 20–30 minutes after injection of technetium 99m-tetrofosmin (after 3 minutes from finish of infusion of dypiridamole) using a dual-head camera. Perfusion quantitation (SSS, SRS, SDS), and LVEF were automatically calculated with the use of Autoquant™ software package. The perfusion was normal when SSS 45%. The follow-up for hard cardiac events (cardiac death or myocardial infarction) was 18,5 ± 7.5 months and completated in 902 pts (89.4%). Results: The frequency of cardiac events/year was major in pts with SSS > 4 (14/393, 3.7%) vs pts with normal perfusion (4/615, 0.7%) and in pts with post-stress LVEF 4). (see table). Conclusions: The evalutation of perfusion and LV function in the same exam (Gated-SPECT) even using dipyridamole stressor provides an additional value for statification of cardiovascular risk in pts with or without suspected CAD. LVEF normal LVEF P SSS (4/584, 0.8%) (1/31, 3.2%) 0.035 SSS > 4 (4/212, 1.8%) (11/181, 6.1%) 0.0001