Can a coronary calcium scan improve the prediction of heart attacks in older divers?

In the July 2015 issue of Undercurrent, an article titled “A better heart-check tool than a stress test?” discusses the possible benefits of a coronary calcium scan for older divers to reduce the risk of experiencing a heart attack while diving.1 This article is a follow-up to a May 2015 Undercurrent report about an overweight 65-year-old diver who died shortly into his dive while on a dive trip.2 That article, which considered preventive options such as a stress test, also presented views from Dr. Alfred Bove and DAN’s Dr. Petar Denoble and Dr. James Chimiak, who agreed with the American College of Physicians (ACP) guidelines that recommend a graded and individualized approach to preventive testing and diagnostics.

Another physician suggests in the July 2015 article, however, that older divers should have a coronary calcium scan, which he claims may provide information that will help them avoid a heart attack on their dive trips. Many walk-in clinics offer the test at a low price. “A coronary calcium scan can tell you years before a positive stress test that you are headed in that direction [of significant coronary disease] so that you can do some kind of intervention,” he said. While the statement has merit, it may be misleading in this context.


Scuba diving related or circumstantial deaths?

“The number of water-related deaths in Cayman this year has already exceeded the annual average, with only half the year gone,” stated Cayman Island News in an article titled “Ocean claims another diver” posted on July 12, 2013.

 It further specifies that one victim died in swimming pool, one fell overboard and one competitive swimmer died during swimming in ocean. The remaining seven were attributed to snorkeling and scuba diving. As the title suggested, this seemed mostly to be scuba divers.

 We checked DAN database and found 20 scuba fatalities in Caymans during the last five years, or an average four per year. For 2013 we found only two scuba fatalities. However, there were other fatalities in water-related activities. Here are the details:



The findings reflect general pattern of water activity related deaths.

  • Drowning in a swimming pool most often affects children as in this case.
  • Falling overboard from the cruiser happens most frequently to young males.
  • Competition-related deaths generally occur in younger athletes, while death during leisurely activities in water regardless whether it is beach going, surface snorkeling or scuba diving occur mainly in older people. Average age in this series was 69.5 years old and all victims in this sample were male.

 Only in two cases was a possible trigger identified: one swimmer succumbed in rough waters and one snorkeler had pulmonary fibrosis that may have contributed to his demise. In all seven cases the death occurred swiftly and fits the definition of sudden cardiac death, which is most often caused by heart disease. In some cases victims may have been diagnosed with cardiac disease previously and in other they felt pretty healthy until their death. Most sudden deaths occur in people with moderate atherosclerotic changes that do not cause any symptoms and may not be detected on annual medical exam, thus call for more strict medical criteria for scuba divers seem unjustified. Besides, neither snorkeling nor beach going requires any certifications or medical approval. With older population staying longer active, it is unavoidable that some deaths occur in public, most of them unrelated to the specific activity.  One could not speculate whether any of these seven deaths could have been prevented without unnecessarily denying older people right to enjoy active life. 

Post written by: Petar Denoble, MD, D.Sc.