Increased Risk of In-Hospital Complications, Including Mortality, Among A-fib Patients Undergoing PCI

Atrial fibrillation is common among patients undergoing PCI and is associated with an increased risk of postprocedural heart failure, cardiogenic shock, and death, according to the results of a new study. In addition, the presence of atrial fibrillation also independently predicts a 32% increased risk of postprocedural bleeding complications.

For researchers, a history of atrial fibrillation should serve as a warning that these patients might be particularly vulnerable to serious in-hospital complications after PCI.

“I think it is important to recognize the increased risk of bleeding and death in this population and adjust the approach to arterial access and pharmacotherapy accordingly,” senior investigator Hitinder Gurm, MD (University of Michigan, Ann Arbor), told TCTMD. “Further, we believe that atrial fibrillation should be included as a marker of baseline comorbidity for benchmarking purposes and something that should be collected in the NCDR registry.”

Published online August 22, 2016, ahead of print in the Journal of the American College of Cardiology, the analysis is based on 113,283 individuals undergoing PCI in the Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2) registry between 2011 and 2014. Of these individuals, 12.3% had atrial fibrillation. The prevalence of PCI-treated patients with atrial fibrillation ranged from 2.5% to 18.4% amongst the 47 hospitals included in the BMC2 analysis.

Overall, compared with individuals without atrial fibrillation, those with the arrhythmia were more likely to have other risk factors for cardiovascular events but less likely to smoke or to present with STEMI. Those with atrial fibrillation were more likely to receive a BMS or angioplasty alone and less likely to receive a DES.

“Our study suggested that BMS were more commonly used in this population and this may relate to the concern about increased bleeding risk with the combination of DAPT and an anticoagulant,” said Gurm. “Along the same lines, [patients with atrial fibrillation] were less likely to get a more potent P2Y12 inhibitor, such as prasugrel or ticagrelor. There is remarkable paucity of data in this space, and the ongoing trials should help clear up some of these issues in the near future.”

In an editorial accompanying the study, Jeptha Curtis, MD, and Joseph Akar, MD (Yale University School of Medicine, New Haven, CT), called atrial fibrillation the “boon and the bane of the practicing cardiologist,” noting that the incidence and prevalence is increasing as the US population ages.

The editorialists note that physicians must grapple with the need to optimize antiplatelet and antithrombotic medications to balance the “unhappy triad” of stent thrombosis, thromboembolic stroke, and bleeding risks.

“What is remarkable is how little evidence we have to guide our decision making in this population,” write Curtis and Akar. “Think about it: drug-eluting stents were introduced into clinical practice 13 years ago. If we conservatively estimate that 5% of PCI patients have atrial fibrillation, we have likely implanted drug-eluting stents in patients with atrial fibrillation at least 250,000 times. . . . We have to do better than this.”

Speaking with TCTMD, Ajay Kirtane, MD (Columbia University Medical Center, New York, NY), said atrial fibrillation is prevalent in elderly populations, and as such, the prevalence is increasing as the population ages. Given this, there is a need to understand the best medication strategies for this group, particularly since PCI patients will require DAPT for their stent and anticoagulation for the arrhythmia, a cocktail that increases the risk of bleeding. Even without atrial fibrillation, said Kirtane, interventionalists will often encounter patients who require anticoagulation for other conditions, such as deep vein thrombosis, pulmonary embolism, or a prior stroke.

In-Hospital Outcomes After PCI  

In the BMC2 registry study, in-hospital outcomes for patients undergoing PCI revealed that those with a history of atrial fibrillation were more likely to develop postprocedural cardiogenic shock, heart failure, stroke, acute kidney failure, and vascular complications, as well as more likely to require dialysis and blood transfusions and to develop bleeding complications. Patients with atrial fibrillation also had higher rates of in-hospital mortality.

Many of these adverse outcomes held up in propensity-matched analysis of 13,498 patients with and without atrial fibrillation. Those with the arrhythmia had significantly higher rates of postprocedural bleeding complications (3.7% vs 2.8%; P < 0.001) and the need for blood transfusion (5.2% vs 4.6%; P = 0.025), as well as more heart failure (4.3% vs 3.3%; P= < 0.001), cardiogenic shock (2.8% vs 2.3%; P = 0.006), and in-hospital mortality (3.0% vs 2.4%; P = 0.001).

To TCTMD, Gurm said most elective PCI is performed with patients off oral anticoagulation, while emergency PCI will be done on whatever therapy the patient is on. In their analysis, as noted, PCI-treated patients were less likely to be treated with more potent antiplatelet therapy, likely because physicians were concerned about the increased risk of bleeding. Gurm said it is not entirely clear why A-fib patients bleed more, though, noting that even those treated with less potent therapy had higher rates of bleeding.

He added that the increase in adverse outcomes in patients with atrial fibrillation was surprising. The researchers suggest the arrhythmia can be viewed as a “harbinger” of serious post-PCI complications. “I personally do not think the risk is mediated by atrial fibrillation, but that atrial fibrillation serves to identify a high-risk cohort of patients at risk for adverse outcomes after PCI,” said Gurm.

At present, said Kirtane, there are consensus recommendations for managing patients with atrial fibrillation undergoing PCI but no true clinical guidelines given the lack of randomized, clinical trial evidence. As a result, there is a wide variation in how patients are medically managed. The consensus recommendations, as well as institutional protocols, often focus on individualizing care, with physicians factoring in the risk of bleeding complications versus the risk of thrombotic events.

“Let’s say there is a patient with atrial fibrillation, but they have a low stroke risk overall and a high bleeding risk,” said Kirtane. “In those people, they might not even be given an anticoagulant due to PCI. On the other hand, if you have somebody with a really high thrombotic risk and their bleeding risk is low, we might just continue with anticoagulation and do the whole case radially. We wouldn’t even stop [anticoagulation] for the procedure. There’s a lot of variables that go into the decision-making for these patients.”

As for the increased risk of adverse clinical outcomes in the A-fib population, Kirtane noted the BMC2 registry data are observational, and that these patients tend to be older and sicker than patients without atrial fibrillation. It’s not easy to separate out the extent to which atrial fibrillation alone is contributing to the increased risk, he said.

Clinical trials testing the optimal treatment strategy are underway, including studies such as PIONEER AF-PCI, REDUAL-PCI, and AUGUSTUS. The randomized, albeit small, WOEST study previously showed an efficacy and safety advantage for the combination of warfarin and clopidogrel versus triple therapy in patients requiring anticoagulation undergoing PCI.

Related Stories:

• Data Gap: Best Strategy Unknown for A-Fib Patients on Newer Anticoagulants Who Need PCI
• Triple Therapy Yields No Thrombotic Benefit, More Bleeding in Older PCI Patients with A-Fib
• Case Study Highlights Risks of A-Fib Patients Undergoing PCI in Absence of Evidence-Based Guidelines