Long-term Cardiovascular Risks of Gonadotropin-releasing Hormone Agonists and Antagonists: a Population-based Cohort Study

AIMS

Gonadotropin-releasing hormone (GnRH) agonists and antagonists, critical medications for prostate cancer (PCa) treatment, may differ in cardiovascular safety. This prospective cohort study aimed to compare the long-term cardiovascular risks between GnRH agonists and antagonists.

MATERIALS AND METHODS

Patients with PCa receiving GnRH agonists or antagonists during 2013-2021 in Hong Kong were identified. Patients with <6 months' prescriptions, who were switching between drugs, had missing baseline prostate-specific antigen level or had a prior stroke or myocardial infarction were excluded. Patients were followed up until September 2021. The primary outcome was major adverse cardiovascular events (MACE) as in the PRONOUNCE trial (MACE_PRONOUNCE), i.e. a composite of all-cause mortality, stroke and myocardial infarction. The secondary outcome was MACE_CVM, i.e. a composite of cardiovascular mortality, stroke and myocardial infarction. Inverse probability treatment weighting was used to balance covariates between groups. The Log-rank test was used to compare the cumulative freedom from the primary outcome between groups.

RESULTS

In total, 2479 patients were analysed (162 GnRH antagonist users and 2317 agonist users; median age 75.0 years, interquartile range 68.0-81.6 years). Inverse probability treatment weighting achieved good covariate balance between groups. Over a median follow-up duration of 3.0 years (interquartile range 1.7-5.0 years), 1115 patients (45.0%) had MACE_PRONOUNCE and 344 (13.9%) had MACE_CVM. GnRH agonist users had lower risks of MACE_PRONOUNCE (Log-rank P < 0.001) and MACE_CVM (Log-rank P = 0.027). However, no differences were observed within 1 year of follow-up (MACE_PRONOUNCE: Log-rank P = 0.308; MACE_CVM: Log-rank P = 0.357). Among patients without cardiovascular risk factors at baseline, GnRH agonist users had lower risks of MACE_PRONOUNCE (Log-rank P < 0.001) and MACE_CVM (Log-rank P = 0.001), whereas no differences were observed in those with such risk factor(s) (MACE_PRONOUNCE: Log-rank P = 0.569; MACE_CVM: Log-rank P = 0.615).

CONCLUSIONS

GnRH antagonists may be associated with higher long-term, but not short-term, cardiovascular risks than agonists in Asian patients with PCa, particularly in those without known cardiovascular risk factors.

The relation between sodium ion content and efflux of labelled sodium ions from yeast

1. The activity of the Na(+) pump in an Na(+)-rich yeast was compared with that in an Na(+)-rich frog sartorius muscle, and found to be very similar to it over the first hour if both were immersed in fluid containing 104mm-Na(+) plus 10mm-K(+). 2. The efflux of labelled Na(+) from an Na(+)-rich yeast into an Na(+)-free medium was investigated. In this Na(+)-free medium, Li(+) or choline replaced the Na(+), and the efflux-content curves obtained with either of these ions were very similar. The curves were sigmoid, reaching or approaching a saturation at the higher internal Na(+) concentrations. 3. The curves obtained with yeast resembled those similarly obtained with frog sartorius muscle by Keynes & Swan (1959), Mullins & Frumento (1963), Harris (1965) and Keynes (1965). The slope of the plot of the logarithm of the Na(+) efflux against the logarithm of the Na(+) concentration in the cells reached its highest value at an internal Na(+) concentration of 15m-equiv./kg. (27m-equiv./l. of cell water). 4. The effect of external K(+) concentration on the efflux-content relationship was examined. An increased K(+) concentration was found to increase the Na(+) efflux by raising the saturation value, which is similar to observations made by Harris (1965) with frog muscle. 5. The effect of increasing the external carbon dioxide concentration was investigated. No effect on the slope of the plot of the logarithm of the Na(+) efflux against the logarithm of the Na(+) content was noticed even when the yeast suspension was equilibrated with 100% carbon dioxide. There was, however, a decrease in the amount of Na(+) efflux on equilibrating the solution with carbon dioxide.