Hemodynamic indexes derived from computed tomography angiography to predict pulmonary embolism related mortality

MRA as the Preferred Test for Pulmonary Embolism During the Iodinated Contrast Media Shortage of 2022: A Single-Center Experience

BACKGROUND. Closure of a GE Healthcare facility in Shanghai, China, in 2022 disrupted the iodinated contrast media supply. Technologic advances have addressed limitations associated with the use of pulmonary MRA for diagnosis of pulmonary embolism (PE). OBJECTIVE. The purpose of this study was to describe a single institution's experience in the use of pulmonary MRA as an alternative to CTA for the diagnosis of PE in the general population during the iodinated contrast media shortage in 2022. METHODS. This retrospective single-center study included all CTA and MRA examinations performed to exclude PE from April 1 through July 31 (18 weekly periods) in 2019 (before the COVID-19 pandemic and contrast media shortage), 2021 (during the pandemic but before the shortage), and 2022 (during both the pandemic and the shortage). From early May through mid-July of 2022, MRA served as the preferred test for PE diagnosis, to preserve iodinated contrast media. CTA and MRA reports were reviewed. The total savings in iodinated contrast media volume resulting from preferred use of MRA was estimated. RESULTS. The study included 4491 examinations of 4006 patients (mean age, 57 ± 18 [SD] years; 1715 men, 2291 women): 1245 examinations (1111 CTA, 134 MRA) in 2019, 1547 examinations (1403 CTA, 144 MRA) in 2021, and 1699 examinations (1282 CTA, 417 MRA) in 2022. In 2022, the number of MRA examinations was four (nine when normalized to a 7-day period) in week 1, and this number increased to a maximum of 63 in week 10 and then decreased to 10 in week 18. During weeks 8-11, more MRA examinations (range, 45-63 examinations) than CTA examinations (range, 27-46 examinations) were performed. In 2022, seven patients with negative MRA underwent subsequent CTA within 2 weeks; CTA was negative in all cases. In 2022, 13.9% of CTA examinations (vs 10.3% of MRA examinations) were reported as having limited image quality. The estimated 4-month savings resulting from preferred use of MRA in 2022, under the assumption of uniform simple linear growth in CTA utilization annually and a CTA dose of 1 mL/kg, was 27 L of iohexol (350 mg I/mL). CONCLUSION. Preferred use of pulmonary MRA for PE diagnosis in the general population helped to conserve iodinated contrast media during the 2022 shortage. CLINICAL IMPACT. This single-center experience shows pulmonary MRA to be a practical substitute for pulmonary CTA in emergency settings.

Evaluating cardiopulmonary function following acute pulmonary embolism

INTRODUCTION

Pulmonary embolism is a common cause of cardiopulmonary mortality and morbidity worldwide. Survivors of acute pulmonary embolism may experience dyspnea, report reduced exercise capacity, or develop overt pulmonary hypertension. Clinicians must be alert for these phenomena and appreciate the modalities and investigations available for evaluation.

AREAS COVERED

In this review, the current understanding of available contemporary imaging and physiologic modalities is discussed, based on available literature and professional society guidelines. The purpose of the review is to provide clinicians with an overview of these modalities, their strengths and disadvantages, and how and when these investigations can support the clinical work-up of patients post-pulmonary embolism.

EXPERT OPINION

Echocardiography is a first test in symptomatic patients post-pulmonary embolism, with ventilation/perfusion scanning vital to determination of whether there is chronic residual emboli. The role of computed tomography and magnetic resonance in assessing the pulmonary arterial tree in post-pulmonary embolism patients is evolving. Functional testing, in particular cardiopulmonary exercise testing, is emerging as an important modality to quantify and determine cause of functional limitation. It is possible that future investigations of the post-pulmonary embolism recovery period will better inform treatment decisions for acute pulmonary embolism patients.

Risk Stratification in Patients with Acute Pulmonary Embolism: Current Evidence and Perspectives

Risk stratification is one of the cornerstones of the management of acute pulmonary embolism (PE) and determines the choice of both diagnostic and therapeutic strategies. The first step is the identification of patent circulatory failure, as it is associated with a high risk of immediate mortality and requires a rapid diagnosis and prompt reperfusion. The second step is the estimation of 30-day mortality based on clinical parameters (e.g., original and simplified version of the pulmonary embolism severity index): low-risk patients without right ventricular dysfunction are safely managed with ambulatory anticoagulation. The remaining group of hemodynamically stable patients, labeled intermediate-risk PE, requires hospital admission, even if most of them will heal without complications. In recent decades, efforts have been made to identify a subgroup of patients at an increased risk of adverse outcomes (intermediate-high-risk PE), who might benefit from a more aggressive approach, including reperfusion therapies and admission to a monitored unit. The cur-rent approach, combining markers of right ventricular dysfunction and myocardial injury, has an insufficient positive predictive value to guide primary thrombolysis. Sensitive markers of circulatory failure, such as plasma lactate, have shown interesting prognostic accuracy and may play a central role in the future. Furthermore, the improved security of reduced-dose thrombolysis may enlarge the indication of this treatment to selected intermediate–high-risk PE.

Prognostic value of CT pulmonary angiography parameters in acute pulmonary embolism

OBJECTIVES

Computed tomographic pulmonary angiography (CTPA) is the first-line test in acute pulmonary embolism (APE) diagnostic algorithm, but its correlation with short-term outcome remains not clear at all. The aim is to determine whether CTPA findings can predict 30-day mortality of patients with APE in Emergency Department.

METHODS

This retrospective monocentric study involved 780 patients with APE diagnosed at the Emergency Department of our institution (period 2010-2019). These CTPA findings were evaluated: embolic obstruction burden score (Qanadli score), common pulmonary artery trunk diameter, right-to-left ventricular ratio, azygos vein and coronary sinus diameters. Comorbidities and fatal/nonfatal adverse outcomes within 30 days were recorded. Troponin I values were correlated with angiographic parameters with multiple logistic regression analysis.

RESULTS

The all-cause and APE-related 30-day mortality rates were 5.9% and 3.6%, respectively. Patients who died within 30 days were older with higher prevalence rates of malignancy. Qanadli score and all CTPA parameters correlate with Troponin I level and the presence of RVD at echocardiography (p values < 0.0001). Instead, RV/LV ratio and coronary sinus diameter correlate with 30-day mortality (p values < 0.05). At the multivariate logistic regression analysis, only coronary sinus and RVD remained significant with an HR = 2.5 (95% CI 1.1-5.6) and HR = 1.9 (95% CI 0.95-3.7), respectively.

CONCLUSION

CTPA quantification of right ventricular strain is an accurate predictor of 30-day mortality. In particular, it seems that a dilated coronary sinus (>9 mm) has an additional prognostic value in association with echocardiographic signs of right-heart disfunction and high Troponin I levels.

Association between computed tomography obstruction index and mortality in elderly patients with acute pulmonary embolism: A prospective validation study

INTRODUCTION

Computed tomography pulmonary angiography (CTPA) has not only become the method of choice for diagnosing acute pulmonary embolism (PE), it also allows for risk stratification of patients with PE. To date, no study has specifically examined the predictive value of CTPA findings to assess short-term prognosis in elderly patients with acute PE who are particularly vulnerable to adverse outcomes.

METHODS

We studied 291 patients aged ≥65 years with acute symptomatic PE in a prospective multicenter cohort. Outcomes were 90-day overall and PE-related mortality, recurrent venous thromboembolism (VTE), and length of hospital stay (LOS). We examined associations of the computed tomography obstruction index (CTOI) and the right ventricular (RV) to left ventricular (LV) diameter ratio with mortality and VTE recurrence using survival analysis, adjusting for provoked VTE, Pulmonary Embolism Severity Index (PESI), and anticoagulation as a time-varying covariate.

RESULTS

Overall, 15 patients died within 90 days. There was no association between the CTOI and 90-day overall mortality (adjusted hazard ratio per 10% CTOI increase 0.92; 95% confidence interval [CI] 0.70-1.21; P = 0.54), but between the CTOI and PE-related 90-day mortality (adjusted sub-hazard ratio per 10% CTOI increase 1.36; 95% CI 1.03-1.81; P = 0.03). The RV/LV diameter ratio was neither associated with overall nor PE-related 90-day mortality. The CTOI and the RV/LV diameter ratio were significantly associated with VTE recurrence and LOS.

CONCLUSIONS

In elderly patients with acute PE, the CTOI was associated with PE-related 90-day mortality but not with overall 90-day mortality. The RV/LV diameter ratio did not predict mortality. Both measures predicted VTE recurrence and LOS. The evaluated CTPA findings do not appear to offer any advantage over the PESI in terms of mortality prediction.

Contrast Circulation Time to Assess Right Ventricular Dysfunction in Pulmonary Embolism: A Retrospective Pilot Study

Objective

To optimize enhancement of pulmonary arteries and facilitate diagnosis of pulmonary embolism (PE), modern computed tomography angiography (CTA) contains a contrast bolus tracking system. We explored the diagnostic accuracy of the time-intensity curves given by this automated system to identify right ventricular dysfunction (RVD) in acute PE.

Methods

114 CTAs with a diagnosis of PE were reviewed. RVD was defined as right-to-left ventricular diameter ratio of 1 or greater. Four parameters on time-intensity curves were identified. Parameters between CTAs with and those without RVD were compared with the Wilcoxon rank-sum test. The ability of the four parameters to discriminate patients with RVD was explored by compiling the area under the operating curves (AUC).

Results

The time needed by the contrast media to reach the pulmonary artery [8 seconds (IQR: 7–9) versus 7 seconds (IQR: 6–8), p<0.01], the time needed to reach 40 Hounsfield units (HU) [11 seconds (IQR: 8.5–14) versus 9.5 seconds (IQR: 8–10.5), p<0.01], and the contrast intensity reached after 10 seconds [19 HU (IQR: 4–67) versus 53 HU (IQR: 32–80), p<0.05] were all statistically different between CTA with and CTA without RVD. Those three parameters changed gradually across severity categories of RVD (p<0.05 for trend). Their AUC to identify RVD ranged from 0.63 to 0.66. The slope of contrast intensity over time was not informative: [31 HU/s (IQR: 20–57) in CTA with, compared to 36 HU/s (IQR: 22.5–53) in CTA without RVD, p = 0.60].

Conclusion

Several parameters of the time-intensity curve obtained by the bolus tracking system are associated with RVD assessed on CTA images. Of those, the time needed to reach a predefined threshold seems to be the easiest to obtain in any CTA without additional processing time or contrast injection. However, the performance of those parameters is globally low.

Early interventional therapy for acute massive pulmonary embolism guided by minimally invasive hemodynamic monitoring

AIM

The aim of this study was to investigate the clinical significance of minimally invasive hemodynamic monitoring in the early catheter-based intervention for acute massive pulmonary embolism (PE).

METHODS

A total of 40 cases with acute massive PE were randomized into experimental and control group with 20 cases in each group. In the experimental group, the hemodynamics was monitored via Vigileo/FloTrac system, while echocardiography was used in the control group. Twelve hours after systemic thrombolysis, catheter-based clot fragmentation and local thrombolysis were employed in the experimental group if Vigileo/FloTrac system revealed hemodynamic abnormality. For the control group, the application of catheter was determined by the findings in echocardiography at 24 hours after systemic thrombolysis.

RESULTS

A total of 12 cases in the experimental group underwent catheter therapy successfully while 4 cases in the control group received the same treatment. Compared to the control group, 12 hours after catheter intervention the experimental group had higher PaO2/FIO2 and right ventricular ejection fraction (RVEF) but lower pulmonary artery systolic pressure (PASP), indicating the effectiveness of Vigileo/FloTrac monitoring. The 28-day survival rates were identical between the groups although one patent in the control group died. Both the RVEF and PASP were significantly improved in the experimental group in 6 months compared to the control group.

CONCLUSIONS

In massive PE, hemodynamic monitoring via Vigileo/FloTrac system might be useful in the decision making for catheter intervention after systemic thrombolysis and might improve the outcomes for patients.