Prognostic implication of myocardial perfusion and contractile reserve in end-stage renal disease: A direct comparison of myocardial perfusion scintigraphy and dobutamine stress echocardiography

Background We aimed to compare the prognostic value of myocardial perfusion scintigraphy (MPS) and dobutamine stress echocardiography (DSE) in patients with end-stage renal disease (ESRD) without known coronary artery disease. Methods Two-hundred twenty-nine ESRD patients who applied for kidney transplantation at our centre were prospectively evaluated by MPS and DSE. The primary endpoint was a composite of myocardial infarction (MI) or all-cause mortality. The secondary endpoint included MI or coronary revascularization (CR) not triggered by MPS or DSE at baseline. Results MPS detected reversible ischemia in 31 patients (13.5%) and fixed perfusion defects in 13 (5.7%) patients. DSE discovered stress-induced wall motion abnormalities (WMAs) in 28 (12.2%) and at rest in 18 (7.9%) patients. MPS and DSE results agreed in 85.6% regarding reversible defects (κ = 0.358; P < .001) and in 90.8% regarding fixed defects (κ = 0.275; P < .001). Coronary angiography detected relevant stenosis > 50% in only 15 of 38 patients (39.5%) with pathological findings in MPS and/or DSE. At a median follow-up of 8 years and 10 months, the primary endpoint occurred in 70 patients (30.6%) and the secondary endpoint in 24 patients (10.5%). The adjusted Cox hazard ratios (HRs) for the primary endpoint were 1.77 (95% CI 1.02-3.08; P = .043) for perfusion defects in MPS and 1.36 (95% CI 0.78-2.37; P = ns) for WMA in DSE. The secondary endpoint was significantly correlated with the findings of both modalities, MPS (HR 3.21; 95% CI 1.35-7.61; P = .008) and DSE (HR 2.67; 95% CI 1.15-6.20; P = .022). Conclusion Perfusion defects in MPS are a stronger determinant of all-cause mortality, MI and the need for future CR compared with WMAs in DSE. Given the complementary functional information provided by MPS vs DSE, results are sometimes contradictory, which may indicate differences in the underlying pathophysiology.

Extremely high troponin levels induced by septic shock: a case report

Background Troponin levels can be elevated in various diseases other than acute myocardial infarction, including sepsis. In diseases without myocardial necrosis, the elevated troponin levels are relatively low and normalize quickly. Case presentation A 61-year-old Japanese man with impaired consciousness was transported to our hospital. He was diagnosed as having pneumonia and septic shock. His condition was severe, but his clinical course was good. However, his troponin level remained extremely high during admission; on the second day, it was higher than the measurable range. We consulted a cardiologist and performed echocardiography and myocardial perfusion scintigraphy but found no new ischemic changes. Conclusion In septic shock, troponin levels can be extremely high, which can persist even after recovery, as in very large myocardial infarctions.

Mechanical Dyssynchrony for Prediction of the Cardiac Resynchronization Therapy Response in Patients with Dilated Cardiomyopathy

Aim To evaluate the predictive value of indexes of left ventricular mechanical dyssynchrony (MD) as determined by data of electrocardiogram (ECG)-gated myocardial perfusion scintigraphy (ECG-MPS) for prediction of the efficacy of resynchronization therapy (RT) in patients with chronic heart failure (CHF).Material and methods This prospective study included 32 patients with nonischemic CHF and standard indications for RT. All patients underwent complete clinical an instrumental examination, including 24-h ECG monitoring and echocardiography (EchoCG). In order to evaluate the left ventricular (LV) myocardial perfusion, contractile function, and MD, myocardial perfusion scintigraphy was performed for all patients at rest prior to RT. In addition to the perfusion defect size at rest and hemodynamic parameters, LV MD was determined. The following indexes were used for analysis of dyssynchronization: phase standard deviation (PSD), phase histogram bandwidth (HBW), and phase histogram asymmetry and steepness. The treatment efficacy was evaluated by the clinical status of patients (clinical condition evaluation scale for CHF patient) and EchoCG at 6 months following RT. The criteria for a positive response to RT were an increase in LV ejection fraction (EF) by 5% and/or a decrease in the LV end-diastolic volume by 15% compared to preoperative values.Results According to ECG-MPS findings, all patients had scintigraphic signs of severe CHF with dilated LV cavity (end-diastolic volume, EDV 246 [217; 269] ml) and also of pronounced mechanical and electrical dyssynchrony. The values of mechanical dyssynchrony were PSD 53 [41; 61], HBW 176 [136; 202], asymmetry 1.62 [1.21; 1.89], and steepness 2.81 [1.21; 3.49]. The QRS duration was 165 [155; 175] msec. Furthermore, the LV perfusion was moderately impaired (perfusion defect size 4 [3; 10] %). Mean follow-up duration after implantation of the resynchronizing device was 6±1.7 mos. According to the selected criteria, 20 (63 %) patients were considered as responders and 12 (37 %) patients as non-responders. Before implantation of the cardiac synchronizing device, responders and non-responders differed only in LV MD (PSD 44 [35; 54] vs. 63 [58; 72]; p=0.0001); HBW 158 [118; 179] vs. 205 [199; 249]; p=0.0001; asymmetry 1.77 [1.62; 2.02] vs. 1.21 [0.93; 1.31]; p=0.0001; steepness 3.03 [2.60; 3.58] vs. 1.21 [0.19; 1.46]; p=0.0001), respectively. A one-factor logistic regression analysis showed that MD values were statistically significant predictors of a positive response to RT. A multi-factor logistic analysis of phase histogram steepness (odds ratio, OR 1.196; 95 % confidence interval, CI 1.04–1.37) and PSD (OR 0.67; 95 % CI 0.47–0.97) were identified as independent predictors for the response to RT. According to results of the ROC analysis, a PSD <55 and a phase histogram steepness >1.54 may predict the effectiveness of RT (AUC= 0.92; р=0.0001).Conclusion LV MD parameters determined with ECG-MPS allow predicting the effectiveness of RT in patients with nonischemic CHF. In this patient group, high values of standard deviation and low values of phase histogram steepness were independent predictors for the absence of response to RT after 6 mos. of follow-up.

DIRECT RESULTS OF CORONARY BYPASS GRAFTING OF PATIENTS WITH THE REDUCED MYOCARDIAL CONTRACTILITY IN TERMS OF MYOCARDIAL PERFUSION SCINTIGRAPHY AND ECHOCARDIOGRAPHY

This article provides an analysis of the results of surgical treatment of patients with various forms of coronary artery disease, the study of the quality and reliability of myocardial revascularization, assessment of patency and functional viability of coronary grafts in the early postoperative period using echocardiography and myocardial perfusion scintigraphy. The retrospective material of our study is based on the results of surgical treatment of 130 patients with coronary artery disease who were operated on in the IHD department over the past year. All patients underwent examination according to a standard protocol: electrocardiography, 24-hour Holter monitoring, selective coronary ventriculography and shuntography, echocardiography, perfusion scintigraphy before and after surgery, drug stress test to assess myocardial perfusion and contractility and its differentiation (ischemia, scarring) with hypoperfusion.

Myocardial perfusion scintigraphy during the COVID-19 pandemic - findings from the university teaching hospital in Slovenia

Funding Acknowledgements Type of funding sources: None. Introduction Department for nuclear medicine in the University medical centre Ljubljana provides nuclear medicine diagnostic procedures for approximately 1.000.000 inhabitants of Slovenia. As many countries in Europe, Slovenia was faced with the first wave of the COVID-19 pandemic in early spring of 2020. Since our country is situated next to the northern part of Italy, where the situation was critical, our Ministry of health issued specific recommendations in March 2020. The aim was to increase hospital capacities for COVID-19 patients through limiting non-urgent diagnostic tests including myocardial perfusion scintigraphy (MPS) and to minimize the spread of the virus into hospital departments. The epidemiologic situation of the first wave resolved within 3 months. In the second wave of the pandemic in autumn 2020, the recommendations on patient care in non COVID-19 cases were less limiting to avoid worsening of non COVID-19 related diseases and patient prognosis. Purpose The aim of our study was to evaluate the influence of the COVID-19 pandemic on MPS in our medical institution. Methods Data on numbers of MPS, clinical characteristics of the patients and findings of MPS were prospectively collected for the first wave (in spring from March 15th to June 15th 2020) and second wave (in autumn from September 15th to December 15th 2020) of the pandemic and were compared with the same periods in 2019. Results During the first wave we performed 40% less MPS, significantly more patients had pharmacological stress and were outpatients than in spring 2019. There were no significant differences in other clinical characteristics and MPS findings (Table 1 and Figure 1). In autumn 2020 we reorganized our schedule to increase the number of patients, which was once again comparable to previous year’s autumn. Although the number of patients was comparable, patients were now significantly older and had more often pharmacological stress, but there were no significant differences in other clinical data or MPS findings (Table 1 and Figure 1). Conclusions In our hospital, during the first wave of COVID-19 pandemic, we performed significantly less MPS than in the same period of the previous year. To minimize the possibility of virus transmission from asymptomatic patients, we followed international recommendations and avoided exercise stress tests but increased the percentage of pharmacological stress tests. A similar approach regarding the type of stress tests was chosen for the second wave in autumn of 2020. However, we decided to increase the number of MPS performed, in order to lessen the negative impact of the pandemic on non COVID-19 related diseases, focusing on coronary artery disease.

The comparison of left ventricular mechanical dyssynchrony obtained by myocardial perfusion scintigraphy and gated blood pool SPECT to predict the result of the cardiac resynchronization therapy

Funding Acknowledgements Type of funding sources: None. Background/Introduction The assessment of left ventricular mechanical dyssynchrony (LV MD) is essential in identifying patients who may benefit from cardiac resynchronization therapy (CRT). Both gated myocardial perfusion scintigraphy (MPS) and gated blood pool SPECT (GBPS) are widely used to LV MD assessment [1,2]. Lack of data is available regarding the comparison of left ventricular MD parameters obtained by MPS and GBPS on cadmium-zinc-telluride (CZT) gamma-cameras and their prognostic value. Purpose to compare two scintigraphic methods – MPS and GBPS in LV MD assessment and to assess the capability of these methods to predict CRT response. Methods This study included 30 heart failure patients referred for CRT. Before CRT all patients underwent rest gated MPS and GBPS with LV MD evaluation on CZT cardiac gamma. Based on the phase analysis, the following indexes were estimated: phase standard deviation (SD) and phase histogram bandwidth (HBW). One year after CRT patients were divided to responders and non-responders. The response criteria were defined as LV end systolic volume decreased by ≥ 15% or LV ejection fraction increase by ≥ 5%, based on echocardiography. Results The correlation between gated MPI indexes and GBPS indexes was suboptimal: SD r = 0.39, p &lt; 0.05; HBW r = 0.48, p &lt; 0.05. Based on Mann-Whitney statistics significant differences between LV MD indexes, assessed by both MPS and GBPS were found: SD LV 56.1 (IQR 50.6 – 64) deg. vs 50.6 (37 - 61) deg., p &lt; 0.05 and HBW LV 188.64 (176 - 213) deg. vs 201.68 (180 - 240) deg., p = 0.03, respectively. The Bland-Altman analysis showed poor agreement between gated MPS and GBPS for SD assessment (p = 0.02) with mean difference value 7.02 (96% CI 1.11 to 12.9). However both MPS and GBPS were comparable in terms of HBW estimation (p = 0.18), with mean difference value of -12.5 (96% CI -31.5 to 6.3).MD indexes derived by MPS differed significantly between CRT responders and non-responders: SD 53.56 (47 – 63.4) deg. vs 62.4 (56-71) deg., p &lt; 0.05; HBW 182.1 (166 - 211) deg. vs 204.3 (179 - 225) deg., p &lt; 0.05. MD indexes obtained by GBPS did not show significant difference in CRT responders and non-responders: SD 51.2 (37 – 62) deg. vs 49.4 (40 – 58) deg., p = 0.92 and HBW 203.4 (186 - 237) deg. vs 198.5 (174 - 240) deg., p = 073. Univariate logistic regression analysis showed that SD and HBW assessed by gated MPS were independent predictors of CRT response: SD (OR = 0.91; 95% CI 0.85-0.97; p &lt; 0.05) and HBW (OR = 0.98; 95% CI 0.96-0.99; p =0.03). However MD indexes obtained by GBPS, did not show statistically significance in prediction of CRT response. Conclusion Gated MPS and GBPS are not interchangeable in terms of left ventricular MD assessment. Left ventricular SD and HBW obtained by gated MPI on CZT gamma-camera showed prognostic significance to predict CRT response.