Tuesday, December 19, 2017

‘Tis The Cardiac Season


Ask just about any paramedic, ER nurse or doctor and they will tell you that the Holidays - from around Thanksgiving to just after New Year's Day - see a spike in sudden coronary attacks.  Events that are commonly called `Christmas Coronaries’ or `Hanukkah Heart Attacks’.

Eighteen years ago, a study looked at the rate of heart attacks in the United States, and found that Acute Myocardial Infarctions (AMIs) run as much 53% higher during the winter months than than during the summer.
Seasonal distribution of acute myocardial infarction in the second National Registry of Myocardial Infarction.

Spencer FA, Goldberg RJ, Becker RC, Gore JM

While cold weather combined with strenuous physical activity (like clearing snow from sidewalks) has often been blamed for this spike, even in balmy Southern California, studies have shown a 33% increase in heart attacks over the holidays (see below).
When Throughout the Year Is Coronary Death Most Likely to Occur?

A 12-Year Population-Based Analysis of More Than 220 000 Cases

Robert A. Kloner, MD, PhD; W. Kenneth Poole, PhD; Rebecca L. Perritt, MS

Non-climate related factors – like over indulgence in food and alcohol, diminished activity levels, forgetting to take prescription medicines, and combined holiday stressors like shopping, running up debt, traveling, meal preparation, and the angst that comes from dysfunctional family gatherings are likely contributors to this yearly spike.

In his 2004 article in Circulation  The ''Merry Christmas Coronary'' and ''Happy New Year Heart Attack'' Phenomenon,  Dr Robert Kloner posited the following reasons for this uptick in excess winter cardiac mortality.


While all are likely contributors, in recent years influenza and other respiratory infections have been increasingly linked to this seasonal increase in heart attacks.

Earlier this year, in Int. Med. J.: Triggering Of Acute M.I. By Respiratory Infection we looked at research  from the University of Sydney that found the risk of a heart attack is increased 17-fold in the week following a respiratory infection such as influenza or pneumonia.
A little over two years ago, in UNSW: Flu Vaccine Provides Significant Protection Against Heart Attacks, we saw a study that found that if you are over 50 - getting the flu vaccine can cut your risk of a heart attack by up to 45%.
Going back even further:
Adding weight to these studies, in 2015 in UK ONS: 2014-15 Excess Winter Mortality Highest Since 1999, we saw evidence of a major spike in winter mortality in the UK when the seasonal H3N2 virus drifted away from the vaccine strain over the previous summer (see CDC HAN Advisory On `Drifted’ H3N2 Seasonal Flu Virus).

Given the expected reduced effectiveness of this year’s flu vaccine ((see ECDC: H3N2 Flu Vaccine Component Likely `Suboptimal',) and the rising tide of H3N2 influenza across the country – the next couple of weeks could prove very busy for the nation’s EMS crews and Coronary care units.
But regardless of the effectiveness of this year’s flu shot, and influenza’s effects on cardiovascular events, even on an `average day’ roughly 1,000 people suffer a Sudden Cardiac Arrest (SCA) in the United States.
This from the Heart Rhythm Association:
  • Sudden Cardiac Arrest (SCA) is a leading cause of death in the United States, claiming more than 350,000 lives each year.
  • Approximately 92% of those who experience sudden cardiac arrest do not survive.
  • SCA kills more than 1,000 people a day, or one person every 90 seconds
What the people who witness these events do in the first few minutes can mean the difference between life and death for the stricken individual. Luckily, hands-only CPR (cardio-pulmonary resuscitation) is easier to do than ever before, and there are thousands of AEDs (automated external defibrillators) stationed in public venues across the nation.

With a few hours of training, you have the potential to save someone’s life. To find a local CPR course contact your local chapter of the American Red Cross, the American Heart Association, or (usually) your local fire department or EMS can steer you to a class.
To learn how to use an AED, you can use this online training module  I wrote about in CPR Skills & AED Simulator.
Of course, despite your best efforts, many SCA victims will not survive. It isn’t at all like on TV, where 75% of  recipients of CPR survive.  Even when cardiac arrests occur inside a hospital, the survival to discharge rate is less than 40%. Outside the hospital, the odds of seeing a good outcome are lower.

While there are no guarantee of success, early and coordinated action taken by bystanders (calling 911, starting CPR, using AED if available) can substantially improve the SCA’s chances of survival.
Obviously, the best way to survive a heart attack is not to have one to begin with.
Which is why I continue to promote getting the seasonal flu shot every year, and practicing good flu hygiene (covering your coughs, washing your hands, staying home when you are sick, etc.) - because, while far from perfect - these steps do reduce your odds of getting sick from the flu.

Because, when it comes to something as serious as a heart attack, every little advantage helps.

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