The incidence rate of major adverse cardiac events (MACEs) after electroconvulsive therapy (ECT)—still commonly used in cases of intractable psychiatric disorders—has been unclear. A new meta-analysis, however, has found that such events occur after ECT in as many as one in 50 patients and after approximately one in 500 treatments.
“Evidence indicates that ECT use may be experiencing a modest resurgence,” said Andreas Duma, MD, an assistant professor of anesthesiology and intensive care at the Medical University of Vienna. “Estimates suggest that over 100,000 people in the U.S. and 1.8 million worldwide receive ECT each year. This is largely due to the fact that injuries and mortality have been reduced in the past 70 years by the use of general anesthesia and improvement in the type of electrical stimulus used.
“Nevertheless, ECT causes hemodynamic perturbations, with sudden shifts between the parasympathetic and sympathetic phases,” he said. “This cardiovascular stress may cause harm. And even though several case reports of MACE after ECT exist, the incidence rate is yet unclear.”
The researchers screened 2,641 publications; data from 284 studies were extracted, of which 54 studies reported MACEs. The publications comprised interventional and observational studies, as well as surveys that investigated ECT; included cardiac event rates; and were published between 1980 and 2016. A host of data were extracted, including MACEs such as myocardial infarction, life-threatening arrhythmia, pulmonary edema, pulmonary embolism, acute heart failure, cardiac arrest and cardiac mortality.
|Table 1. Incidence of Major Adverse Cardiac Events Associated With ECT|
|Adverse Event||Incidence Per 1,000 Patients (95% CI)||Incidence Per 1,000 ECT Procedures (95% CI)|
|Myocardial infarction||1.11 (0.00-2.58)||0.77 (0.00-1.58)|
|Life-threatening arrhythmia||14.82 (8.63-21.02)||0.87 (0.38-1.37)|
|Acute pulmonary edema||7.59 (0.00-20.09)||1.22 (0.22-2.23)|
|Pulmonary embolism||0.70 (0.00-2.06)||0.70 (0.00-2.06)|
|Acute heart failure||19.98 (5.85-34.11)||2.08 (0.61-3.55)|
|Cardiac arrest||0.95 (0.00-1.89)||0.15 (0.01-0.28)|
|ECT, electroconvulsive therapy|
As Dr. Duma reported at the 2017 annual meeting of the American Society of Anesthesiologists (abstract A1093), the most frequent cardiac event was acute heart failure, with an incidence rate of 19.98 per 1,000 patients (95% CI, 5.85-34.11) and 2.08 per 1,000 ECT treatments (95% CI, 0.61-3.55). “ECT patients usually receive seven to 10 treatments,” he said, “so the incidence rate per treatment is usually one-seventh to one-tenth of the incidence rate per patient.” Table 1 illustrates the complete incidence list of MACEs associated with ECT.
“We also examined mortality,” Dr. Duma said, “and found an all-cause mortality rate of 0.13 per 1,000 patients.” Of note, 23 of 79 deaths were of cardiac origin. Table 2 shows the mortality associated with ECT.
|Table 2. Incidence of Mortality Associated With ECT|
|Mortality||Incidence Per 1,000 Patients (95% CI)||Incidence Per 1,000 ECT Procedures (95% CI)|
|Studies Reporting No Adverse Events Included|
|All-cause mortality||0.13 (0.00-0.27)||0.05 (0.01-0.08)|
|Cardiac deaths||0.04 (0.00-0.15)||0.01 (0.00-0.03)|
|Studies Reporting No Adverse Events Excluded (Sensitivity Analysis)|
|All-cause mortality||0.33 (0.01-0.64)||0.06 (0.02-0.11)|
|Cardiac deaths||0.18 (0.00-0.46)||0.02 (0.00-0.05)|
|ECT, electroconvulsive therapy|
“These results,” Dr. Duma concluded, “suggest that MACE may occur in up to one in every 50 patients and one in every 500 ECT procedures. The most common events are acute heart failure, arrhythmia and pulmonary edema, and almost a third of mortality may be attributable to cardiac events.”
Session co-moderator Claude Abdallah, MD, an associate professor of anesthesiology and pediatrics at the George Washington University School of Medicine and Health Sciences, in Washington, D.C., said the results of the meta-analysis possibly may change the way clinicians approach these patients. “The clinical implications are relevant in describing both the incidence and etiologies of associated morbidity and mortality with electroconvulsive therapy,” she told Anesthesiology News. “The results of this meta-analysis would help the care team and the anesthesiologist in their discussion of possible adverse events and in assessing the risk/benefit of the procedure in their practice, as well as being ready and prepared to treat any of these adverse events.”