Regional CZT myocardial perfusion reserve for the detection of territories with simultaneously impaired CFR and IMR in patients without obstructive coronary artery disease: a pilot study

OBJECTIVES

To assess the diagnostic performances of CZT myocardial perfusion reserve (MPR) for the detection of territories with simultaneous impaired coronary flow reserve (CFR) and index of microcirculatory resistance (IMR) in patients without obstructive coronary artery disease.

METHODS

Patients were prospectively included before being referred for coronary angiography. All patients underwent CZT MPR before invasive coronary angiography (ICA) and coronary physiology assessment. Rest and dipyridamole-induced stress myocardial blood flow (MBF) and MPR were quantified using 99mTc-SestaMIBI and a CZT camera. Fractional flow reserve (FFR), Thermodilution CFR, and IMR were assessed during ICA.

RESULTS

Between December 2016 and July 2019, 36 patients were included. 25/36 patients presented no obstructive coronary artery disease. A complete functional assessment was performed in 32 arteries. No territory presented a significant ischemia on CZT myocardial perfusion imaging. A moderate yet significant correlation was observed between regional CZT MPR and CFR (r = 0.4, P = .03). Sensitivity, specificity, positive and negative predictive value, and accuracy of regional CZT MPR versus the composite invasive criterion (impaired CFR and IMR) were 87 [47% to 99%], 92% [73% to 99%], 78% [47% to 93%], 96% [78% to 99%], and 91% [75% to 98%], respectively. All territories with a regional CZT MPR ≤ 1.8 showed a CFR < 2. Regional CZT MPR values were significantly higher in arteries with CFR ≥ 2 and IMR < 25 (negative composite criterion, n = 14) than in those with CFR < 2 and IMR ≥ 25 (2.6 [2.1 to 3.6] versus 1.6 [1.2 to 1.8]), P < .01).

CONCLUSION

Regional CZT MPR presented excellent diagnostic performances for the detection of territories with simultaneously impaired CFR and IMR reflecting a very high cardiovascular risk in patients without obstructive coronary artery disease.

Does whole-body bone SPECT/CT provide additional diagnostic information over [18F]-FCH PET/CT for the detection of bone metastases in the setting of prostate cancer biochemical recurrence?

BACKGROUND

To assess whether whole-body (WB) bone SPECT/CT provides additional diagnostic information over [18F]-FCH PET/CT for the detection of bone metastases in the setting of prostate cancer biochemical recurrence (PC-BR).

METHODS

Patients referred for a PC-BR and whom benefited from a WB bone SPECT/CT and FCH PET/CT were retrospectively included. Tests were classified as positive, equivocal, or negative for bone metastases. A best valuable comparator (BVC) strategy including imaging and follow-up data was used to determine the metastatic status in the absence of systematic histological evaluation.

RESULTS

Between January 2011 and November 2017, 115 consecutive patients with a PC-BR were evaluated. According to the BVC, 30 patients had bone metastases and 85 patients did not present with bone lesions. The sensitivity, specificity, positive and negative predictive values were respectively 86.7% [69.3-96.2], 98.8% [93.6-100.0], 96.3% [78.7-99.5], and 95.5% [89.4-98.1] for WB bone SPECT/CT and 93.3% [77.9-99.2], 100.0% [95.8-100.0], 100.0 and 97.7% [91.8-99.4] for FCH PET/CT. There was no significant difference in diagnostic accuracy of bone metastases between WB Bone SPECT/CT (AUC 0.824 [0.74-0.90]) and FCH PET/CT (AUC 0.829 [0.75-0.90], p = 0.41).

CONCLUSION

Despite good performances for the diagnosis of bone metastases in PC-BR, WB bone SPECT/CT does not provide additive diagnostic information over concomitant FCH PET/CT.

Impact of obstructive sleep apnea on the obesity paradox in critically ill patients

OBJECTIVE

Patients admitted to an intensive care unit (ICU) frequently suffer from multiple chronic diseases, including obstructive sleep apnea (OSA). Until recently OSA was not considered as a key determinant in an ICU patient's prognosis. The objective of this study was to document the impact of OSA on the prognosis of ICU patients.

METHODS

Data were retrospectively collected concerning adult patients admitted to ICU at two university hospitals. In a nested study OSA status was checked using the hospital electronic medical records to identify exposed and unexposed cases. The following outcomes were considered: length of stay in the ICU, ICU mortality, in-hospital mortality, ventilator-associated pneumonia (VAP).

RESULTS

Out of 5146 patients included in the study, 289 had OSA at ICU admission (5.6%). After matching, the overall impact of OSA on length of ICU stay was not significant (p = .24). In a predefined subgroup analysis, there was a significant impact of OSA on the length of ICU stay for patients with BMI over 40 kg/m² (IRR: 1.56 [1.05; 2.32], p = .03). OSA status had no impact on ICU or hospital mortality and VAP.

CONCLUSION

In general, known OSA did not increase the ICU stay except for patients with both OSA and morbid obesity.