Study Evaluates Outcomes of Catheter-Based Therapy for Patients with Cancer and Intermediate- or High-Risk Pulmonary Embolism
01/26/2024
January 11, 2024—A study published online in Catheterization and Cardiovascular Interventions by Leiva et al evaluating outcomes of patients with cancer hospitalized with intermediate- or high-risk pulmonary embolism (PE) found a lower risk of in-hospital death or cardiac arrest and a higher risk of major bleeding after treatment with catheter-based therapies (CBT) as compared with no CBT.
KEY FINDINGS
- CBT was associated with a decreased risk of in-hospital death or cardiac arrest and an increased risk of major bleeding.
- As compared with systemic thrombolysis alone, treatment with CBT alone was associated with a lower risk of in-hospital death or cardiac arrest and no difference in major bleeding.
Investigators used the National Inpatient Sample to identify patients with ICD-10 codes for a primary or secondary diagnosis of PE and at least one code for cancer from October 1, 2015 to December 31, 2018.
The primary outcome measures included in-hospital death or cardiac arrest and major bleeding, defined as a composite of in-hospital gastrointestinal, intracranial, procedure-related, and other bleeding (retroperitoneal, hemoperitoneum, epistaxis, and hemoptysis).
Statistical analysis compared outcomes of CBT use versus no CBT use in patients with intermediate- or high-risk PE (both combined and separately) and looked at outcomes between patients who received CBT or systemic thrombolysis alone. Propensity scores were estimated using nonparsimonious multiple logistic regression, and then scores were used to perform inverse probability treatment weighting (IPTW) analysis. Variables that were unbalanced after IPTW were adjusted using IPTW multivariable logistic regression.
A total of 2,084 patients with cancer and intermediate- or high-risk PE were included (1,231 with intermediate-risk PE, 861 with high-risk PE; mean age, 66.4 years; 49.1% female; 31.7% non-White race). Of these, 136 (6.5%) were treated with CBT: 94 (69.1%) with CBT alone, 35 (25.7%) with mechanical thrombectomy alone, and 7 (5.1%) with both. Overall mortality was 27.3%.
After IPTW, CBT was associated with a lower rate of in-hospital death or cardiac arrest (16.9% vs 27.9%; P < .001) and a higher rate of major bleeding (22.6% vs 11.9%; P = .006), including postprocedural bleeding (16.8% vs 11.9%; P < .001) and other bleeding (7.4% vs 4.6%; P < .001), as compared with no CBT. After adjusting for unbalanced variables of hypertension and vasopressor use after IPTW, patients who received CBT still had lower odds of in-hospital death and cardiac arrest (adjusted odds ratio [aOR], 0.54; 95% CI, 0.46-0.64) and higher odds of major bleeding (aOR, 1.41; 95% CI, 1.21-1.65).
After analyzing by PE risk type, the risk of in-hospital death or cardiac arrest was lower with CBT in both intermediate (aOR, 0.52; 95% CI, 0.36-0.75) and high-risk PE groups (aOR, 0.48; 95% CI, 0.33-0.53), and major bleeding risk was increased only in the intermediate-risk group (aOR, 2.12; 95% CI, 1.67-2.69; high-risk PE group: aOR, 0.84; 95% CI, 0.66-1.07).
In an analysis of patients who underwent either CBT (N = 124) or systemic thrombolysis alone (N = 165), patients treated with CBT alone had a lower risk of in-hospital death or cardiac arrest as compared with those treated with systemic thrombolysis alone (aOR, 0.49; 95% CI, 0.33-0.74), but there was no difference in risk of major bleeding (aOR, 1.12; 95% CI, 0.74-1.68).
Investigators noted several study limitations, including its retrospective design and use of the National Inpatient Sample database, potential residual unmeasured confounding despite statistical adjustments, and use of ICD-10 codes to classify PE types and cancer diagnoses.
Results of this study suggest that CBT may be useful in cancer patients with intermediate- or high-risk PE, an important finding considering that this patient population is typically excluded from clinical trials, noted the investigators.
CARDIAC INTERVENTIONS TODAY ASKS…
Study authors Orly Leiva, MD, and Sripal Bangalore, MD, with New York University Grossman School of Medicine, in New York, New York, commented on the current approach to intermediate- and high-risk PE in special patient populations and how this study helps inform clinical practice.
PE trials have typically excluded special patient populations, such as pregnant patients and patients with cancer. What does the current decision-making for CBT versus no CBT look like for cancer patients with PE? Does this algorithm change in light of the study’s results?
Typically, if a patient with cancer is thought to have a fair long-term prognosis (typically > 1 year, depending on the institution and operator), the same treatment decision algorithm is generally applied to those patients. I think this study highlights the possible efficacy of CBT in patients with cancer, but clinicians should take these results with a grain of salt given the retrospective nature and potential for unmeasured confounders. That being said, these results suggest that cancer should not be considered a contraindication for CBT in PE, and decisions for CBT should be made in a multidisciplinary fashion with the incorporation of the patient’s overall prognosis and goals of care into the decision-making process.
The CBT group was mainly composed of patients who received catheter-directed thrombolysis, while a minority received mechanical thrombectomy or both. Does this have any implications for the increased risk of major bleeding seen in this study? How might this be clarified in future studies?
Although CBT in theory delivers thrombolytics locally, it is known that systemic exposure is possible and occurs with CBT. Patients with cancer have myriad reasons for increased bleeding, including thrombocytopenia, compromised mucosal integrity due to cancer therapies, and tumor invasion. Therefore, it is difficult to discern the exact mechanisms of bleeding in our study. Further prospective studies with more granular data on laboratory values, cancer staging, and cancer treatments are needed to characterize the risk of bleeding.
You note that this study highlights the importance of evaluating this high-risk patient population in future trials. What are the key outcomes and unanswered questions to evaluate going forward?
I think confirming our results in a prospective and randomized clinical trial is important going forward. Additionally, further risk stratification for bleeding is important especially among patients with cancer.
Cancer patients often have significant comorbidities confounding treatment options and timing of interventions if deemed appropriate. How can cancer teams and PE response teams (PERTs) ensure timely care in this population?
Collaboration of cancer teams and PERTs is important, especially for prognostication of cancer and other risk factors for cardiovascular disease in cancer. Cardio-oncology is a growing field and incorporation of cardio-oncology in patients with PE and cancer should also be considered and investigated in future studies.