May 17, 2012

May 17, 2012
HIV Linked to Risk of Sudden Cardiac Deaths

Welcome to another day in my life. Today is Thursday and I hope you are having a safe and great week so far. It is another busy week for Dab the AIDS Bear and me.

One of the downsides to long term living with HIV and taking HIV medications is the increased risk of strokes and heart attacks. Today I will be talking on this issue again.

People with HIV have more than four times the risk of sudden cardiac death than the general population, researchers reported.

In a large cohort of HIV-positive people in San Francisco, the mean rate of sudden cardiac death over a 10-year period was 2.6 per 1,000 person-years, according to Zian Tseng, MD, of the University of California San Francisco, and colleagues.

That was 4.46 times higher than expected given the background rate of sudden cardiac death in the city (6.73 based on 2007 rate and population), Tseng and colleagues reported in the May 15 issue of the Journal of the American College of Cardiology.

The underlying mechanism that causes the increased risk remains unclear, the researchers noted, but the findings suggest that physicians treating HIV patients should be aware of the danger.

The study arose out of earlier research into sudden death in San Francisco, Tseng said in a statement.

"I noticed that many of these cases involved individuals with HIV infection who were dying suddenly," he said. "I wondered if there was some sort of connection there."

To find out, he and colleagues studied medical records of 2,860 consecutive HIV patients, all at least 18-years-old, enrolled between April 1, 2000, and Aug. 31, 2009 at a public HIV clinic in San Francisco.

Over a median follow-up of 3.7 years, there were 230 deaths in the cohort. Most of those, as expected, were from AIDS (131 or 57%), 30 (13%) met criteria for sudden cardiac death. There were also 25 deaths from other natural disease and 44 from overdose, suicide, or unknown cause.

All told, the 30 sudden cardiac deaths accounted for 86% of all 35 cardiac deaths, the researchers found.

Patients who died of sudden cardiac death were older than those who died of AIDS, had more robust immune systems, and had lower viral loads. Specifically, the average age of people who died of AIDS was 44.9, compared with 49 for those who had a sudden cardiac death. The difference was significant at P<0.02.

Also, the median count of CD4-positive T cells was 87 cells/mm3 of blood for those who died of AIDS, compared with 312 cells/mm3 of blood for those who had sudden cardiac death. The difference was highly significant at P=0.0001.

And for those who died of AIDS, the median plasma viral load was 4.8 log10 copies of HIV RNA/mm versus 3.8 log10 copies of HIV RNA/mm for those who had sudden cardiac death. The difference was significant at P=0.009.

Those findings suggest that patients are at risk for sudden cardiac death "even in the setting of mild HIV disease," the researchers argued.

On the other hand, some risk factors were evident, they reported.

Compared with those who died of AIDS or other natural causes combined, those who died of sudden cardiac death had elevated rates of the following:

Prior myocardial infarction: 17% versus 1% (P<0.0005)
Cardiomyopathy: 23% versus 3% (P<0.0005)
Heart failure: 30% versus 9% (P<0.004)
Arrhythmias: 20% versus 3% (P<0.003)

Tseng and colleagues cautioned that the study was retrospective and it is possible that the rate of sudden cardiac death was over-estimated. Nor did chart data allow extraction of the duration of antiretroviral treatment, which might be a risk factor.

Finally, they noted, patients with prevalent cardiovascular disease were over-represented in the cohort, which might have affected the outcome.

They called for further studies to look at the underlying mechanisms in this patient population, "which may include inflammation, antiretroviral therapy interruption, and concomitant medications," they said.

Now you know the rest of the story. Hope you have a safe and great Thursday!

Until we meet again; here's wishing you health, hope, happiness and just enough.

big bear hug,

Daddy Dab