Incremental Diagnostic Performance of Combined Parameters in the Detection of Severe Coronary Artery Disease Using Exercise Gated Myocardial Perfusion Imaging

Abstract

PurposeMyocardial perfusion imaging (MPI) using gated single-photon emission tomography (gSPECT) may underestimate the severity of coronary artery disease (CAD). This study aimed to evaluate the significance of combined parameters derived from gSPECT, as well as treadmill stress test parameters, in the detection of severe CAD.MethodsA total of 211 consecutive patients referred for exercise MPI between June 2011 and June 2013 (who received invasive coronary angiography within six months after MPI) were retrospectively reviewed. Exercise MPI was performed with Bruce protocol and 201Tl injected at peak exercise. Gated SPECT was performed using a cadmium-zinc-telluride camera and processed by QPS/QGS software. Perfusion defect abnormalities such as sum stress score (SSS); sum difference score, algorithm-derived total perfusion deficits, transient ischemic dilatation ratios of end-diastolic volumes and end-systolic volumes, post-stress changes in ejection fraction, and lung/heart ratio (LHR) were calculated. Treadmill parameters, including ST depression (STD) at the 1st and 3rd minutes of recovery stage (1’STD and 3’STD), maximal STD corrected by heart rate increment (ST/HR), heart rate decline in 1st and 3rd minutes of recovery stage, recovery heart rate ratio (HR ratio), systolic and mean blood pressure ratios (SBP ratio and MAP ratio) during recovery phase were recorded. Diagnostic performances of these parameters were analyzed with receiver operating characteristic (ROC) analysis and logistic regression for detection of left main (≥ 50%) or 3-vessel disease (all ≥ 70% luminal stenosis) on invasive angiography.ResultsAmong various MPI and treadmill parameters used for detection of severe CAD, SSS and ST/HR had the highest AUC (0.78, 0.73, p = NS) and best cut-off values (SSS > 6, ST/HR > 17.39 10-2mV/bpm), respectively. By univariate logistic regression, all parameters except 1’HRR, 3’HRR, SBP and MAP ratios increased the odds ratio of severe CAD. Only increased L/H ratio, 3’STD, and HR ratio remained significant after multivariate regression. The predicted values of combined MPI and treadmill parameters (LHR, 3’STD, and HR ratio) gave the best ROC (AUC: 0.91) than any individual parameter or parameter combination.ConclusionsOf all treadmill and gSPECT parameters, the combination of MPI and treadmill parameters can offer better diagnostic performance for severe CAD.

El puntaje de Framingham ayudaría en la estratificación del riesgo de pacientes con ergometría positiva y SPECT normal

“…En relación con las variables predictoras de eventos, publicaciones previas sugieren que el sexo masculino, la edad avanzada y la presencia de enfermedad arterial coronaria conocida se asocian con un mayor riesgo de eventos cardiovasculares 19,20 . La elevada tasa de eventos en este subgrupo de pacientes sugiere que en pacientes de alto riesgo cardiovascular, el valor predictivo negativo de la prueba SPECT se ve afectado por la presencia de hallazgos clínicos o ECG anormales en la prueba de esfuerzo.…”

Diagnostic value of cadmium-zinc-telluride myocardial perfusion imaging versus coronary angiography in coronary artery disease

“…Meanwhile, the control cases are different in elected study, some included patients with history of ischemic heart disease [13] , but other patients with very low pretest likelihood of CAD . [24] Third, other potential factors contributed to the pooled result, for instance previous history of myocardial infarction, body position changes during examination and obesity, because of the limited of information, these features cannot be precisely explained. Image quality is very important for new diagnostic methods, and due to insufficient information about the image quality of CZT-SPECT, we cannot provide more details…”

El dilema clínico frente a los pacientes con ergometría positiva y prueba de perfusión miocárdica con SPECT normal

“…Entre el 4 y el 24 % de estudios SPECT presentan signos de isquemia en la ergometría a pesar de una perfusión miocárdica normal, y aunque el pronóstico en términos de sobrevida global es bueno, el riesgo de presentar infarto no fatal, de revascularización y de internación se encuentra ligeramente aumentado en estos pacientes [15][16][17][18][19] .…”