Australians with schizophrenia are more than two times as likely to have coronary heart disease and up to three times more likely to experience sudden cardiac death than the general population, a new review reveals.
Sydney cardiologist and one of the review authors, Professor Leonard Kritharides, said cardiotoxicity from antipsychotic drugs and under treatment of cardiovascular risk factors combined with comorbid chronic diseases and a lack of coordinated care has created a ‘perfect storm’ for the alarmingly poor CV outcomes that are associated with these patients.
He says there’s an opportunity for cardiologists to make a significant difference in the long-term outcomes of people with schizophrenia.
“These patients have a huge problem with life expectancy, it’s substantially less than the general population – about 25 years less – and the striking thing is, in most cases, that gap in life expectancy is not related to suicide or the schizophrenia but to the medical issues they have that are undertreated.”
Speaking to the limbic Professor Kritharides said that standard CVD algorithms are likely to underestimate risk in people with schizophrenia, which could, in part, explain the high rates of undertreatment of CV risk factors.
According to the review, the rates of untreated dyslipidaemia and hypertension in schizophrenia have been reported to be up to 88% and 62% of patients respectively.
Meanwhile, patients with schizophrenia are 47% less likely to receive cardiac intervention — such as angioplasty or coronary artery bypass grafting — than those without mental illness.
In terms of assessing relative risk and lifetime risk, Professor Kritharides also said that cardiovascular risk factors might be even more important in the young than in the old.
“In young patients, where a 5-year absolute risk of cardiovascular events is low, preoccupation with short term risk probably really underestimates the long term loss of life associated with risk factors in young adulthood or middle age and the life time benefits of attending to risk factors early.”
Cardiotoxicity associated with antipsychotic agents commonly used in the management of schizophrenia adds to the complexity of treating patients with schizophrenia, Professor Kritharide says.
For example, clozapine can lead to myocarditis or cardiomyopathy but this doesn’t mean all patients will need to come off the drug.
“The challenge here is for the cardiologist to discriminate between mild cardiac impairment and either myocarditis or cardiomyopathy,” Professor Kritharides said.
“These patients need careful review so that we can make good decisions about whether or not they have progressive and serious impairment in cardiac function that is not remediable with conventional treatment or whether they might have an incidental mild impairment of cardiac function that may not require cessation of treatment.”
According to Professor Kritharides that’s a distinction that any cardiologist can make as long as they’ve got good communication with the psychiatrist and confident about being able to follow up the patient.