Prior Cancer Diagnosis Increases Mortality Risk After Primary PCI for STEMI

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A history of cancer greatly increases the risk of all-cause and cardiac mortality following primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI), according to a study published online September 23, 2013, ahead of print in the American Journal of Cardiology.

Matthijs A. Velders, MD, of Medical Center Leeuwarden (Leeuwarden, The Netherlands), and colleagues studied 3,423 consecutive STEMI patients enrolled in a multicenter Dutch registry who underwent primary PCI from 2006 to 2009. Of these, 208 patients (6.1%) had a history of cancer. The cancer population was further subdivided according to time elapsed between diagnosis of cancer and primary PCI:

• More than 3 years before
• 6 months to 3 years before
• Less than 6 months before

Patients with history of cancer were older, more often women, and more frequently had hypertension.

Highest Mortality Linked to Most Recent Cancers

Compared with those who did not have prior cancer, patients with a cancer history had longer median intervals between STEMI diagnosis and balloon inflation (86 minutes vs.79 minutes; P = 0.024), were less likely to receive a stent (92.3% vs. 95.9%; P = 0.014), were more frequently treated with intra-aortic balloon pumps (6.7% vs. 3.9%; P = 0.041), and were less likely to receive abciximab (67.2% vs. 75.1%; P = 0.012) or be discharged on beta-blockers (84.2% vs. 90.5%; P = 0.005).

Previous cancer patients also had higher all-cause and cardiac mortality (table 1).

Table 1. Mortality

Additionally, when time between cancer diagnosis and PCI was calculated, those with the most recent diagnoses had the highest mortality rates at all follow-up durations, whether all-cause (in-hospital, 19.0%; 7 day, 23.8%; 1 year, 50.0%) or cardiac (in-hospital, 19.0%; 7 days, 23.8%; 1 year, 28.9%).

After multivariate adjustment, any history of cancer was found to predict cardiac mortality at 7 days. Stratification by time of cancer diagnosis showed this association to be primarily driven by patients with a diagnosis in the 6 months prior to PCI (table 2).

Table 2. 7-Day Cardiac Mortality by Time of Diagnosis

In explanatory analyses, anemia at admission (adjusted HR 3.40; 95% CI 1.52-7.57; P = 0.003) and anemia plus cardiogenic shock (adjusted HR 2.71; 95% CI 1.21-6.09; P = 0.016) explained much of the effect size of recent cancer on cardiac mortality. However, no association between chemotherapy and cardiac mortality was observed.

Cancer-Specific Effect

According to the study authors, the link between cancer-related anemia and death is not surprising since anemia “is known to predict cardiovascular death and heart failure in patients with STEMI because of the increased myocardial oxygen demand associated with the increased stroke volume and tachycardia required to maintain adequate systemic oxygen delivery.”

What is surprising, they note, is the lack of association between adverse outcome and chemotherapy, suggesting a cancer-specific effect on prognosis after STEMI. This may be explained, Dr. Velders and colleagues say, by the presence of cancer procoagulant and tissue factor expressed by tumors.

While they note that more research is needed in this area, the study authors say balloon angioplasty without stents might be preferable in cancer patients to limit the duration of dual antiplatelet therapy. “If stents need to be used, those with fast endothelialization rates, that is, bare-metal or everolimus-eluting stent[s], should likely be preferred to minimize the risk of stent thrombosis,” they write. “Also, coronary artery bypass grafting may have advantages over stenting.”

 

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Source:
Velders MA, Boden H, Hofma SH, et al. Outcome after ST elevation myocardial infarction in patients with cancer treated with primary percutaneous coronary intervention. Am J Cardiol. 2013;Epub ahead of print.

 

 

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