ICD-Recipient Anxiety High at First, Improved Over a Year--Shocks or Not

December 03, 2009

December 3, 2009 (Rochester, Minnesota and Toronto, Ontario) — Patients who received implantable cardioverter defibrillators (ICDs) frequently suffered from excess anxiety and posttraumatic stress, as measured with validated tests, which in most cases declined significantly over the following year, in a rare prospective study exploring the psychological effects of device implantation [1].

Levels of depression didn't change much over time. Interestingly, the minority of patients who received ICD shocks and those who didn't had similar scores on all psychological tests throughout the follow-up.

Among the observational study's implications: testing patients too soon after device implantation can overestimate the prevalence of longer-term, clinically important device-related anxiety; on the other hand, as many as 10% of ICD recipients can still have such symptoms a year after implantation, observe the authors, led by Dr Suraj Kapa (University of Pennsylvania, Philadelphia), in a report published online November 18, 2009 in Pacing and Clinical Electrophysiology.

As cardiologists and as these patients' physicians, we have the opportunity to identify an enormous number who might be suffering from psychopathologies.

Why anxiety and posttraumatic stress generally declined throughout the study isn't known, Kapa acknowledged for heartwire . "In the immediate postimplantation period, there are a lot of factors that could affect test responses. We put multiple restrictions on the patients, and we advise them of the multiple risks associated with ICD implantation," he said. "This is speculation, but these various restrictions might increase their anxiety." If so, anxiety might decline as the restrictions are lifted.

Or, Kapa said, many ICD recipients have a recent history of ventricular tachycardia or MI causing significant anxiety that partly resolves after device implantation, "suggesting that the ICD itself might not be what's causing severe psychopathology--it may be other underlying disease processes."

Half the cohort, for example, had a history of MI, a quarter had an LVEF <35%, at least half had some degree of heart failure, and half had devices for secondary prevention. Three-fourths were on beta blockers, half were on statins, and half were on ACE inhibitors. Only a handful, a few percent of the cohort, were taking medications for depression or anxiety.

A secondary purpose of the study, according to Kapa, was to demonstrate the feasibility of the standard psychological assessment instruments Hospital Anxiety and Depression Scale (HADS), Impact of Events Scale-Revised (IES-R, which measures posttraumatic stress), and Short Form 36 Health Survey (SF-36) in a population of ICD recipients. Other, mostly cross-sectional, studies in this population have usually relied on other instruments, he said.

The study's 223 device recipients at two major centers underwent the tests at baseline (within two months of ICD implantation) and six and 12 months later. The proportion of patients with anxiety and posttraumatic stress fell off significantly, while depression was as common at six and 12 months as at the start.

Prevalence of Clinical Anxiety and Depression and Posttraumatic Stress Disorder (PTSD)A Tracked Over One Year in 223 Patients With ICDs

Psychological condition Baseline (%) 6 mo (%) 12 mo (%)
Depression 10 11 11
Anxiety 35b 15 15
PTSD 21c 12 13
a. PTSD gauged by the Impact of Events Scale-Revised test, depression and anxiety by the Hospital Anxiety and Depression Scale

b. p<0.001 vs 6 and 12 months

c. p<0.05 vs 6 and 12 months

Moreover, average performance also improved significantly over 12 months for both the HADS and IES-R tests (p<0.001 for mean score changes on both tests).

Five patients (<3%), all with secondary-prevention devices, experienced "electrical storm," defined as at least three shocks within a 24-hour period. In all cases, Kapa said, the multiple discharges were for VT or VF--that is, delivered appropriately.

Their posttraumatic stress scores were significantly higher at baseline compared with other patients, averaging 29.6 on the IES-R vs 14.6 (p<0.01). Anxiety and depression scores improved over 12 months in both groups. Speculating, Kapa said that could mean patients with electrical storm were sicker as a group and "may have had some other illness mediating their anxiety. People who are sicker might be more likely to develop frequent VT or VF that might lead to electrical storms." It fits, he added, that they may be more likely to have anxiety or posttraumatic stress.

"As cardiologists and as these patients' physicians, we have the opportunity to identify an enormous number who might be suffering from psychopathologies," Kapa said. "By using these screening tools to identify them, it will give us the opportunity to refer many of these patients either back to their primary-care physician for further assessment or potentially to psychiatry."


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