The high-sensitivity cardiac troponin T biomarker could be used to identify those chemotherapy patients at increased risk of cardiotoxicity, according to results of the Spanish GECAME/CARDIOTOX study presented at this congress.
Early detection of those at risk of cardiotoxicity would help identify those who would benefit from heart failure therapies. The GECAME/CARDIOTOX study was based on a registry of patients from 19 Spanish hospitals treated with cardiotoxic anticancer drugs. They were followed-up with serial echocardiographic and biochemical measurements for two years after starting chemotherapy, and investigators Carlos Alvarez-Ortega and colleagues from University Hospital La Paz, Madrid, explored the role of biomarkers in early diagnosis.
More than 200 consecutive patients, 76.7% of whom were women, had blood samples drawn at baseline, 21 days, three months, six months and one year after starting chemotherapy. Levels of the two cardiac troponin isoforms cardiac troponin T (cTnT) and cardiac troponin I (cTnI) were measured, along with NT-proBNP and Galectin-3. Altogether, 59.5% of patients had been diagnosed with breast cancer, 34.7% with leukaemia or lymphoma and 5.8% with other tumours.
Results for cTnT at three months showed that 120 patients had cTnT levels above the 99 percentile cut-off (where 99% of normal healthy patients have levels below this). Of these 120 patients, 20 went on to develop cardiotoxicity during follow-up giving a positive predictive value of 17% (meaning that only 17% of all patients with cTnT levels above the 99th percentile developed cardiotoxicity).
For the 102 patients with cTnT levels below the 99 percentile, seven developed cardiotoxicity. This gave a negative predictive value of 93% (meaning that 93% of patients with cTnT levels below the 99th percentile did not develop cardiotoxicity). NT-proBNP and Galectin-3 levels did not vary significantly at follow-up.
‘The results suggest that asymptomatic patients with cTnT values below the 99 percentile at three months might not need a very close cardiac follow-up, because they are at low risk of developing left ventricular dysfunction,’ said Alvarez-Ortega. More research, he added, is now needed with a larger series of patients to introduce multiple variables into the risk score.
The reason NT-proBNP and Galectin-3 showed no variation, he suggested, was because these biomarkers occur later in the natural history of HF.
Programme number P3632. High-sensitivity T troponin for early detection of cardiotoxicity among patients on chemotherapy.
Many cancer patients dying from heart failure related to chemotherapy do so without ever having received a HF diagnosis or treatment, according to a study described at this congress. This Australian study further found that almost two-thirds of chemotherapy patients who died from HF did so within three years of treatment.
It is now well established that a number of chemotherapy drugs and radiotherapy are cardiotoxic, with anthracyclines and trastuzumab known to be particularly damaging to cardiac cells.
Narelle Berry from Flinders University, Adelaide, described the study on behalf of a multidisciplinary team. They aimed to explore whether there were differences in cancer patients diagnosed with HF who subsequently died of HF compared to cancer patients who died of HF without a prior HF diagnosis. The study is part of a series designed to understand the health care ‘journey’ of patients with cardiotoxicity after chemotherapy and the stage at which HF interventions might best be introduced.
The team linked data from the Queensland Cancer Registry to the Hospital Admitted Patient Data Collection and the deaths’ registry. Results showed that within the cohort of 15,987 patients receiving chemotherapy for blood, lymphatic and breast cancers, 1062 were diagnosed with HF and 14,925 were not. Among the cohort of 4894 patients who subsequently died, 279 who had been diagnosed with HF died from HF (known as the HFA group), and 455 who had never been diagnosed with HF died from HF (known as the NHFA group).
Within the first year of cancer diagnosis 30.5% of the HFA group had died from HF compared to 33.4% of the NHFA group, and by three years 60% of the HFA group had died compared to 62% of the NHFA group. Furthermore, HFA patients had a median of four chemotherapy cycles compared to NHFA patients who had a median of six. Finally, 71% of the deceased patients who had an index HFA died within one year of that index HF admission.
‘As has been shown previously, mortality is high and occurs quickly in patients with cancer and HF,’ said team leader Robyn Clark. ‘What’s new from our study is the high proportion of cancer patients who develop cardiotoxicity and die without ever having a diagnosis of HF or treatment. This points to a need for chemotherapy patients to be monitored more closely and undergo detailed risk factor screening,’
Programme number 4047. Heart failure mortality following cancer treatment: a linked health data analysis of blood, lymphatic and breast cancer patients (1996-2009).
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