Primary PCI Underused but Just as Effective in Cancer Patients With STEMI

Patients with cancer, including hematologic, breast, and lung cancer, who present with STEMI fare just as well with primary PCI as those without cancer, according to the results of a new study.

While primary PCI is underutilized in this high-risk group, with just half of lung cancer patients, for example, taken to the cath lab for revascularization, researchers found there was no significant difference in the risk of in-hospital major adverse cardiovascular and cerebrovascular events or all-cause mortality based on whether STEMI patients had cancer.

“Overall, these findings should provide some reassurance or evidence for operators who might be more cautious and potentially worried about causing harm in this high-risk group,” lead investigator Mohamed O. Mohamed, MBBCh (Keele University/Royal Stoke University Hospital, Stoke-on-Trent, England), told TCTMD.

Senior author Mamas Mamas, BMBCh, DPhil (Keele University/Royal Stoke University Hospital), agreed, saying the new study quantifies the in-hospital benefit and clearly shows that patients with cancer derive a similar reduction in all-cause mortality and MACCE as those without cancer. “That’s a really important message to get out there,” he said.

Cezar Iliescu, MD (University of Texas MD Anderson Cancer Center, Houston), who wasn’t involved in the study, praised the investigators for the “high-quality” research, emphasizing that it should be assumed cancer patients with STEMI are going to the cath lab for primary PCI unless they are called off by oncology. “For the majority of procedures, we go ahead and do them standard,” he told TCTMD. “If you have to err, you just go ahead and do it. We always err on doing the procedures.” 

Iliescu, who led the Society for Cardiovascular Angiography and Interventions consensus statement on the management and considerations of cardio-oncology patients in the cath lab, said the new data are part of a growing body of evidence showing that intervening in cancer patients with STEMI provides a very meaningful difference in outcomes. Historically, the approach in cancer patients with concomitant cardiovascular disease had been to first address the cancer, with the heart’s needs coming second.

“We’ve learned over the years, it’s exactly the opposite of what we should do,” said Iliescu. “A patient with good cardiovascular status and good cardiac function is more likely to survive and have a better [cancer] outcome. It expands throughout the whole spectrum, from interventions to cardiovascular fitness, where anything you can do to improve cardiovascular outcomes makes the [cancer] patient better off.”

National Inpatient Sample

Published today in European Heart Journal – Acute CardioVascular Care, the researchers identified 1,870,815 hospitalizations for STEMI between 2004 and 2015 using data from the National Inpatient Sample. Of these, 2.1% had a diagnosis of cancer, including 11,251 with a hematologic malignancy and 9,719, 9,538, 4,675, and 3,749 with prostate, lung, breast, and colon cancer, respectively. Overall, 82.3% of patients without cancer underwent primary PCI, but this percentage was much lower in those with a cancer diagnosis. The rate of primary PCI ranged from 54.2% to 70.6% in the cancer patients, with those who had lung cancer least likely to be sent to the cath lab for revascularization.

We always err on doing the procedures. Cezar Iliescu

Using propensity-score matching, the researchers calculated the average treatment effect of PCI versus no-PCI among patients without cancer and within each group of cancer patients (prostate, lung, breast, colon, and hematologic). There was a strongly negative association between primary PCI and in-hospital MACCE, as well as mortality, in patients with and without cancer. The average treatment effect, according to the researchers, “was at least equal to, or in some cases greater, than the no-cancer group.” In terms of adverse events, the average treatment effect of primary PCI on major bleeding and acute stroke was not statistically significant, although PCI did have a positive treatment effect on acute stroke in patients with colon cancer.

In the propensity-matched cohort of 111,738 individuals hospitalized for STEMI, including 93.3% with a cancer diagnosis and 6.7% without, the adjusted probability of MACCE, mortality, and acute stroke in the cancer and no-cancer groups was significantly lower if they were treated with primary PCI versus no PCI. Here again, the probability of acute stroke was higher among colon cancer patients if they were slated for primary PCI. There was no major difference in the probability of major bleeding between the primary PCI and no-PCI subgroups across all cancer subtypes.

Mamas said it’s not uncommon to encounter patients who have cancer presenting with STEMI, noting there are data showing that the risk of acute MI is highest within the first 30 days of cancer diagnosis. The reason is that some of the treatments, such as chemotherapeutic 5-fluorouracil, can cause a range of cardiotoxicities, including MI. The antiangiogenic tyrosine kinase inhibitors are also associated with a broad spectrum of cardiovascular toxicities. Nonetheless, there can be a real reluctance to take patients to the cath lab for invasive treatment because of concerns about ischemic events and major bleeding.

“It really makes operators pause,” he said, noting they may also be reluctant to treat the STEMI patient with primary PCI because they’re pessimistic about the cancer prognosis. “As cardiologists, we perhaps think of worst-case scenarios.” 

Mohamed agreed, noting that randomized controlled trials, and even observational studies, looking at primary PCI in the setting of STEMI have largely excluded patients with cancer, leaving physicians with questions about the risk-benefit trade-off. At present, the clinical guidelines recommend physicians use their best judgement when it comes to clinical decision-making, taking into account cancer staging and prognosis.

Adapting Clinical Care

Despite the positive findings, Mamas said physicians will need to adapt their approach when treating patients with cancer. For example, imaging to ensure the stent is well expanded and apposed in the vessel plays a particularly important role in this population as physicians aim to minimize the risk of stent thrombosis. Additionally, stent selection is more important in this high-risk group, particularly in certain types of cancer. In colon cancer and hematologic malignancies, said Mamas, there is a high risk of bleeding, but thrombotic complications predominate in lung cancer.

“If you have a patient with colon or GI cancer, it’s important is choose a stent platform where there is data for shorter [dual antiplatelet therapy (DAPT)] regimens because of their high risk of bleeding,” said Mamas, suggesting DES such as BioFreedom (Biosensors) or Resolute Onyx (Medtronic). Additionally, tailoring the types of agents used as part of DAPT might be important depending on the cancer type. “It’s not just about doing the primary PCI,” he said, “but doing primary PCI for the types of cancer you’re dealing with and with a view toward optimizing patient outcomes postdischarge.”

Iliescu agreed the goal is to “tailor the stent platform to the cancer agenda.” After discussions with the oncologist, who will advise on DAPT duration, they’ll select a stent based on that recommendation. Like Mamas, Iliescu said there are a number of DES with positive data supporting 1-month DAPT. They’ll turn to the Cobra PzF (CeloNova Biosciences) stent with a nanocoated polymer if they need to cut DAPT to just 14 days.

What will move the field forward, added Iliescu, are studies with dedicated stents targeting specific cancers. Nonetheless, the message that PCI is safe and equally effective in cancer patients is an important one that needs to be heard by the cardiovascular community.  

Interestingly, the new analysis by Mohamed, Mamas, and colleagues sprung from a previous study looking at time trends, treatment, and clinical outcomes of acute MI patients with a cancer diagnosis. In that work, the group observed that patients with cancer were less likely to receive invasive treatment but when they did fared significantly better. When the findings were posted on Twitter, Mamas said he received a message from study coauthor Harriette Van Spall, MD (McMaster University, Canada), suggesting a propensity-matched study looking at trends and clinical outcomes of patients with cancer undergoing primary PCI.  

“It goes to show that when you post articles on Twitter and you highlight what’s going on, people do read them and come to you with ideas,” said Mamas.