June 24, 2020
Retrospective Analysis Shows Lower Long-Term Mortality for Paclitaxel DCB Versus POBA to Treat Femoropopliteal Lesions
June 24, 2020—Tanja Böhme, MD, et al published findings from a retrospective analysis showing that the long-term mortality rate was lower after paclitaxel drug-coated balloon (DCB) angioplasty than after plain old balloon angioplasty (POBA) of femoropopliteal lesions in a real-world practice. Known comorbidities, risk factors, and disease severity were identified as mortality predictors—but not paclitaxel, concluded the investigators. The study is available online in Journal of the American College of Cardiology (JACC): Cardiovascular Interventions.
The investigators performed a retrospective mortality analysis of patients with at least 3-year follow-up who underwent balloon-based endovascular therapy of femoropopliteal lesions. There were 7,357 patients with femoropopliteal lesions who were treated within the study period receiving either DCB angioplasty or POBA. Of those, 1,579 fulfilled the study criteria: 514 patients were treated with POBA without crossover to a paclitaxel-coated device during follow-up; 1,065 patients were treated with DCB angioplasty.
As summarized in JACC: Cardiovascular Interventions, at a mean follow-up of 52.0 ± 20.5 months (median, 51 months), the investigators found:
- The mortality incidence was 27.8% after POBA versus 16.9% after DCB angioplasty (P < .001).
- For a cohort excluding patients age > 80 years, the mortality rate after POBA treatment was significantly higher than after DCB (23.6% vs 12.3%; P < .001).
- For the entire cohort, independent predictors for mortality were age (P < .001), type of treatment (P = .009), hyperlipidemia (P = .01), diabetes mellitus (P = .01), renal insufficiency (P = .007), stroke (P = .017), and Rutherford-Becker class 4 (P < .001).
- After propensity score matching, independent mortality predictors were POBA treatment (P = .035), age (P < .001), stroke (P = .025), and renal insufficiency (P = .007).
Commenting on the study to Endovascular Today, the study's senior investigator, Professor Thomas Zeller, MD, noted, "Paclitaxel dose expressed as DCB length was not correlated to mortality rate." He added, "It [is] worth highlighting the unique composition of the control group, which is 100% paclitaxel naïve in contrast to all recent publications related to paclitaxel mortality analysis."
In an accompanying Editorial Comment entitled, "Retrospective Real-World Studies of Paclitaxel and Mortality: Defining the Many Faces of Bias," available online in JACC: Cardiovascular Interventions, Krishna Rocha-Singh, MD, addresses limitations of the findings by Böhme et al as well as those of any observational study, particularly in the landscape of the paclitaxel controversy during the past 18 months.
According to Dr. Rocha-Singh, the limitations in the Böhme study include single-center enrollment, selection bias, informational bias, and attrition bias, which he details in the editorial.
Dr. Rocha-Singh stated, "[O]wing to the inherent potential for moderate and large biases, the role of observational studies is generally limited, as potential biases can obscure, overestimate, and even reverse the real effect of the treatment under question. As such, their role in the direct assessment of the impact of a particular treatment on a major outcome (ie, mortality) must be carefully scrutinized." He advised, "[I]t is essential to acknowledge the possible multiple confounding variables, extraneous influences, which may impact a conclusion."
He continued, "Close attention to study methodologies and inherent, undisclosed bias is essential to weighing the veracity of a study’s conclusions. Böhme et al leave many questions unanswered, including the mechanism of observed increase in late-term POBA-related mortality and how the risk-benefit profile of these devices may shift across patient populations."
"Regardless, critical analysis of any conclusion is part of a larger story that builds a body of knowledge and allows for the further consideration of the effect of DCBs versus POBA on mortality, if any. However, as our medical community turns to address the challenges of the COVID-19 (coronavirus disease 2019) pandemic, this paclitaxel mortality issue will take its rightful 'back burner' place to our more pressing concerns," concluded Dr. Rocha-Singh in JACC: Cardiovascular Interventions.
For more information, visit Continuing Coverage: Paclitaxel in PAD, Endovascular Today's online compendium on the paclitaxel safety controversy.