Ayala F

Is the addition of ECG gating to technetium-99m sestamibi SPET of value in the assessment of myocardial viability ? An evaluation based on two-dimensional echocardiography following revascularization

The main goal of this study was to evaluate whether the addition of ECG gating to technetium-99m sestamibi single-photon emission tomography (SPET) perfusion imaging assists the prediction of recovery of regional wall motion abnormalities after revascularization. Thirty-six patients with coronary artery disease were included in the study. All had wall motion abnormalities, and 31 (86%) had a clinical history of myocardial infarction. Coronary artery bypass surgery was performed in 18 patients and angioplasty in the remainder. All underwent ECG-gated and non-gated SPET at rest and after intravenous dipyridamole. Two-dimensional echocardiography was performed at a mean of 27 days before revascularization and at a mean of 69 days following revascularization to assess segmental wall motion changes. Perfusion prior to revascularization was analysed qualitatively and quantitatively on gated and non-gated SPET, and the results compared with those of echocardiography. Bullseye parameters were obtained from a normal database, generated from data in 40 normal volunteers, using dipyridamole ECG-gated and non-gated sestamibi SPET. There was good concordance between gated and non-gated qualitative analysis (79% with kappa=0.65) for normal, viable or necrotic segments. Gated SPET predicted functional recovery in 27 of 35 (77%) segments showing echocardiographic improvement while non-gated SPET did so in 30 of 39 (77%) such segments. Gated SPET predicted no functional recovery in 20 of 45 (44%) segments that did not show improved wall motion after revascularization, while with non-gated SPET the figure was 18 of 51 (35%). The positive predictive values of gated and non-gated SPET with regard to the recovery of wall motion following revascularization were 52% and 48%, while the negative predictive values were 71% and 67%, respectively.99mTc-sestamibi had a low predictive value for recovery of function if visual assessment was used in the analysis of SPET data. Quantitative bullseye sestamibi parameters (defect extension and severity, reversibility and percentage change in extension), from gated or non-gated studies, appear best to distinguish which segments will display improved motility on the echocardiogram after revascularization. The addition of ECG gating does not significantly increase the predictive value of SPET imaging with regard to recovery of function.

Simultaneous assessment of function and perfusion during dipyridamolehandgrip Tc-99m sestamibi imaging in chronic coronary artery disease

The main goal of this work was to know the value of ventricular function in addition to perfusion Tc-99m sestamibi images in the assessment of coronary artery disease (CAD) when using dipyridamole (DIP) associated to isometric exercise. We analyzed 52 patients with suspected CAD; 40 of them had coronary lesions ≥ 50% and 12 patients without CAD, conforming study and control groups, respectively. Twenty-eight patients had prior myocardial infarction. A two-day sestamibi protocol was employed with i.v. DIP-handgrip and rest injections, acquiring ECG-gated first pass and planar perfusion images.Sensitivity for perfusion images was 85% and specificity was 91.7%. There was no change between rest and DIP ejection fraction (EF) in controls. CAD patients presented a significant EF decrease with DIP (p: 0.0015). Patients with ischemia in perfusion images had larger EF decrease (p: 0.0001). For the analysis, an EF drop ≥ 5% and any wall motion abnormality (WMA) were considered as having an abnormal response to DIP. CAD sensitivity improved significantly to 92.5% when adding EF drop and to 90% when adding WMA parameters, but specificity decreased to 75% with EF drop, and to 58.3% with WMA. In conclusion, first pass parameters from DIP-isometric exercise in addition to perfusion images are not a significant help in the assessment of CAD.

Síndrome de Tako-Tsubo, caracterización clínica y evolución a un año plazo.

Background: Tako-Tsubo Syndrome (TTS) is characterized by transient regional systolic dysfunction of the left ventricle (LV), mimicking myocardial infarction. It accounts for 0.9-1.2% of all acute coronary syndromes (ACS). Aim: To describe the incidence and characteristics of TTS within our population. Material and methods: All patients diagnosed with ACS and TTS were selected from a clinical registry of all the coronary angiographies done in our hospital. Clinical features during initial presentation, hospital evolution and one year follow-up are reported. Results: The first case diagnosed in our hospital occurred in 2001. Since then, 4433 coronary angiographies were done to patients with ACS until 2014 and 37 corresponded to TTS (0.83% incidence). The mean age of patients was 64 years, 73% were female, and 62% had hypertension. All patients had an identifiable trigger factor, abnormal EKG and elevated troponin. The coronary angiography did not show lesions in 97%. However, all had the characteristic extensive segmental-motility alteration with a mean ejection fraction of 44%. All patients were treated initially as an ACS. Seven patients had complications, namely acute cardiac failure in six and stroke in one. No patient died. At one year of follow-up, 100% showed normal segmental motility and ejection fraction, no patient had a new episode of TTS and all were alive. Conclusions: TTS is rare and the incidence found in this study is slightly lower than that reported elsewhere. TTS mimics ACS and it should be suspected by its clinical, electrocardiographic and enzymatic particularities. Coronary angiography helps to rule out other diagnosis. All patients normalize motility and ventricular function, which is the definitive differential feature respect to ACS.

Angiografía coronaria: indicación, resultados y complicaciones en 5.000 pacientes consecutivos

Background: There are guidelines about equipment, premises, personnel, indications and complications rates for coronary angiography, that every center performing this procedure should adhere. Aim: To report the experience with 5.000 coronary angiographies and to assess the compliance of the center with the current guidelines. Material and methods: Prospective registry of 5.000 patients aged 60±11 years (3.475 males) subjected to coronary angiography since 1992, assessing all aspects of the procedure with special emphasis on complications. Results: The indications for 80% of procedures was suspected coronary atherosclerosis. The main risk factors were hypertension and smoking. Coronary atherosclerosis was demonstrated in 62%, mainly one vessel disease. These were two deaths due to the procedure (0.04%), three patients (0.06%) had an acute myocardial infarction or a stroke. These figures are lower than referential values. Conclusions: In this center, coronary angiography is a safe procedure, with complications rates that are even lower than referential values