Check Troponin in RCC Patients Before Checkpoint-VEGFR Inhibitor Combo


In JAVELIN Renal 101, those with high levels had more heart events with avelumab-axitinib

A photo of a blue rubber gloved hand holding a test tube of blood labeled: Troponin T - Test

Advanced renal cell carcinoma (RCC) patients with high serum levels of troponin T had a greater risk of serious cardiac events when treated with an immune checkpoint inhibitor and VEGFR inhibitor combination, data from the phase III JAVELIN Renal 101 trial indicated.

For patients assigned to the avelumab (Bavencio) plus axitinib (Inlyta) arm, 17.1% of those with high troponin T values had a major cardiovascular adverse event (MACE) versus 5.2% of those with lower values (relative risk 3.31, 95% CI 1.19-9.22), reported Brian I. Rini, MD, of Vanderbilt University Medical Center in Nashville, and colleagues.

But this difference was not seen in the sunitinib (Sutent) arm, at 5.1% versus 5.7% for those with high and low troponin T levels, respectively (RR 0.89, 95% CI 0.20-3.98), according to findings appearing in the Journal of Clinical Oncology.

“We suggest that baseline assessment of troponin T levels may be considered when starting treatment with an ICI [immune checkpoint inhibitor] plus a VEGFR inhibitor, particularly in patients with cardiovascular risk factors,” Rini and his colleagues wrote. “Patients with high troponin T levels should be monitored closely for cardiac symptoms during treatment, potentially including ECG monitoring, and a cardiologist should be involved in patient management from the outset of treatment.”

However, the authors added, cardiac history “should not exclude patients from receiving ICI plus VEGFR combination therapy.”

Left ventricular ejection fraction (LVEF) decline in the trial was significantly more frequent in the combination arm (8.5% vs 1.6%), but most patients recovered and the decline was not associated with other significant cardiac events or symptoms, Rini’s group reported. Thus, “routine monitoring of LVEF in asymptomatic patients is not recommended.”

JAVELIN Renal 101 randomized 866 RCC patients with previously untreated advanced disease 1:1 to either the PD-L1 checkpoint inhibitor avelumab plus VEGFR inhibitor axitinib or to sunitinib, a multi-targeted receptor tyrosine kinase inhibitor. Results of the phase III study led to the FDA approval of avelumab-axitinib in this setting.

The rationale for the current study, the authors noted, is that checkpoint inhibitors and VEGFR inhibitors have been associated with cardiovascular adverse events, “creating a theoretical potential for an increased incidence of MACE with combination treatment.” This study, they said, is the first to prospectively assess LVEF decline and serum cardiac biomarkers in patients treated with a checkpoint inhibitor plus VEGFR inhibitor.

Approximately 60% of patients in each arm of the study had a history of hypertension. At data cutoff, median exposure to avelumab, axitinib, and sunitinib was 37.2, 39.2, and 31.7 weeks, respectively.

Overall, MACE (defined as grade ≥3 cardiovascular adverse events) occurred in 31 patients (7.1%) in the combination arm, and 17 patients (3.9%) in the sunitinib arm, a non-significant difference that was reduced in exposure-adjusted analyses, Rini and his colleagues observed.

Other cardiovascular baseline risk factors and serum cardiac biomarkers were not significantly predictive for MACE, the authors noted, although there was trend toward an association with dyslipidemia in the combination arm.

“Because of the small number of patients with MACE in our study, the predictive value of serum biomarkers other than troponin T cannot be ruled out,” wrote Rini and his colleagues. “Larger studies are needed to confirm the findings in this study.”

Blood Test Marker Could Gauge Risks After Heart Surgery


About 2 million adults worldwide undergo heart surgery each year, and checking blood levels of a certain protein could help assess their risk of death within 30 days, a new study shows.

Blood tests to check levels of troponin (a type of protein found in heart muscle) have long been used to evaluate the risk of death and serious complications after heart attack, but the tests are not commonly done after heart surgery.

This new study found that elevated troponin levels were associated with an increased risk of death after heart bypass or open heart surgery.

“This study is a landmark for the health teams taking care of patients after cardiac surgery,” said study co-author André Lamy, a professor of surgery at McMaster University in Canada.

“For the first time, we have a marker that is fast and reliable for the monitoring of these patients after cardiac surgery,” Lamy said in a university news release.

This study included nearly 16,000 adult heart surgery patients, average age 63, in 12 countries. By 30 days after surgery, more than 2% of patients had died, and about 3% had experienced a major vascular complication, such as heart attack, stroke or a life-threatening blood clot.

The patients’ troponin levels were measured before and daily for the first few days after surgery.

“We found that the levels of troponin associated with an increased risk of death within 30 days were substantially higher  200 to 500 times the normal value  than troponin levels that surgical teams are currently told defines the risk of a patient having one of the most common complications after heart surgery  myocardial injury, a heart muscle injury associated with increased deaths,” said lead study author P.J. Devereaux. He’s a senior scientist at McMaster and a cardiologist at Hamilton Health Sciences.

The study was published March 2 in the New England Journal of Medicine.

SOURCE: McMaster University, news release, March 2, 2022

Diagnosing Acute Coronary Syndromes: The Troponin Conundrum


As the sensitivity of Tn assays rises, electrocardiographic and clinical evidence of ACS become more — not less — important in treatment decisions.

The diagnostic criteria for myocardial infarction (MI) are obtained from the triad of clinical presentation, electrocardiogram (ECG) changes, and serial cardiac enzyme or biomarker measurements. In recent years, the emphasis on biomarkers — specifically, troponin (Tn) — has increased, while ECG findings and clinical symptoms have received relatively little attention. Nonetheless, a detectable Tn level alone does not equal a diagnosis of MI.

TROPONIN AND MYOCARDIAL DAMAGE

Acute coronary syndromes (ACS) is a general term used when clinical symptoms and signs of myocardial ischemia are caused by obstruction of flow through the coronary arteries, and it typically has included both MI and unstable angina. A European Society of Cardiology and American College of Cardiology joint consensus document (published in 2000, updated in 2007) explicitly defines MI as myocardial necrosis secondary to ischemia, which can also occur in ACS without MI. Cardiac Tn is an extremely specific marker of cardiac injury; however, myocardial damage is not specific to either MI or ACS.

Several new high-sensitivity Tn (hsTn) assays are able to detect levels of Tn that would register as zero with older, conventional assays. The advantages of the hsTn assays — greater sensitivity in identifying myocardial injury and potential for earlier detection of MI — come at the cost of a reduction in specificity for the diagnosis of ACS. Indeed, in a recent report, investigators used cardiac computed tomography to confirm a mechanistic association between elevated hsTn levels and myocardial damage, not only in patients with ACS but also in those without ACS. Even with conventional Tn assays, patients can have detectable Tn levels because of etiologies other than ACS; the use of hsTn is likely to increase such false-positive findings.

We need to reassess the currently held belief that Tn is released only from irreversibly injured myocardial cells. In a recent study, marathon runners had significant elevations in Tn levels after a race. The authors postulated two alternative mechanisms for increased Tn values after heavy exertion: true myocardial injury resulting from the breakdown of myocytes, and cytosolic release of the biomarker. In the marathon study, delayed-enhancement cardiac magnetic resonance imaging supported a cytosolic release, and the authors of a recent review concluded that increased membrane permeability is a likelier mechanism than myocardial necrosis for exercise-induced Tn release. Researchers have now determined that hsTn can be detected in healthy populations and that elevated levels are associated with increased cardiovascular risk (Am Heart J 2010; 159:972).

The goal of diagnosing any medical condition is to classify patients by prognosis, pathophysiology, and response to specific therapies. An elevated Tn level in a patient with sepsis, hypertensive emergency, pulmonary embolism, hypotension, renal failure, or any of several other conditions indicates that myocardial damage or even nonthrombotic MI (the extreme end of the spectrum of demand ischemia) has occurred, producing leakage of low levels of Tn and likely indicating a poor prognosis. However, an elevated Tn level does not mean that the patient has ACS, and therefore should not necessarily lead to ACS-directed care. To distinguish ACS from nonocclusive conditions, a compatible clinical syndrome must be accompanied by a change in Tn levels — rising, falling, or both.

CONCLUSION

High-sensitivity assays will enable physicians to both confirm and exclude MI sooner than is now possible, but serial testing at 0, 4, and 8 hours remains necessary. Moreover, the tests are useful for diagnosing (“ruling in”) certain high-risk conditions (demand ischemia and MI) but not for excluding (“ruling out”) the diagnosis of unstable angina — also a high-risk situation for the patient but one in which troponin leak might not occur. Overreliance on Tn and failure to consider ECG findings and clinical presentation appropriately can lead to both over- and underdiagnosis of MI, each of which carries its own set of hazards.

J. Stephen Bohan, MD, MS, FACP, FACEP, and Joel M. Gore, MD

Published in Journal Watch Emergency Medicine August 5, 2010