Despite the beautiful views and respite from street noise, living on the upper floors of a high-rise apartment or condo building may have a hidden health-related downside.

Canadian researchers have found that the survival rate for high-rise residents who experience a cardiac arrest is poorer for those who live on the upper floors compared to those who live on the lower ones. In fact, the higher up people live, the smaller their chances of surviving, according to the study’s findings.

And we’re not talking very high up. The study, which was published Monday in the Canadian Medical Association Journal (CMAJ), defined “higher floors” as the third floor and above.

The most likely reason for these findings, say the study’s authors, has to do with something they call “vertical response delay”: It takes longer for first responders to reach people on higher floors.

As background information in the study points out, more than 400,000 out-of-hospital cardiac arrests occur in Canada and the United States each year. A cardiac arrest strikes when the heart suddenly malfunctions and stops beating. It is not the same as a heart attack, which occurs when a blockage halts blood flow to the heart.

The survival rate is extremely low for people who experience cardiac arrest. Less than 10 percent live to be eventually discharged from a hospital. Rapid defibrillation and high-quality cardiac pulmonary resuscitation (CPR) are crucial for survival. Each one-minute delay to defibrillation, say the study’s authors, is associated with a drop in survival of 7 percent to 10 percent.

That’s why it’s so essential that first responders reach the patient quickly.

Study details

For the current study, researchers examined data collected from 8,216 Canadians who suffered out-of-hospital cardiac arrest in private residences (homes, townhouses, apartments and condos) and were treated by paramedics in the greater Toronto area between 2007 and 2012. Of these cardiac arrests, 5,998 (73.0 percent) occurred below the third floor, and 1,844 (22.4 percent) occurred at or above the third floor. The researchers had to exclude 374 events (4.6 percent) from their analysis because the floor number was missing from the records.

The average age of patients in the study was 71, and 60 percent of them were male.

Overall, 3.8 percent of the patients (300 of 7,842) survived and were eventually released from a hospital. The researchers then dove deeper into the data to see if survival corresponded to the floor the patients were on when they experienced their cardiac arrest.

They found that 252 (4.2 percent) of the 5,998 patients with cardiac arrest below the third floor survived, compared with 48 (2.6 percent) of the 1,844 patients on the third floor or above.

The data also revealed that survival was “negligible” for people living on the 16th floor or above (2 of 216 patients, or 0.9 percent), and that there were no survivors among the 30 patients who lived above floor 25.

In a floor-by-floor analysis of the data, the researchers found “a statistically significant decrease in survival to hospital discharge for each floor of patient contact.”

The study’s authors say that one of the most likely explanations for the study’s findings is the increased time it takes for first responders to reach patients on upper floors — and to then get them to the hospital.

A previous study by one of the authors found it takes an extra 90 seconds for first responders to reach patients on the third floor or higher.

Research has also shown, write the researchers, that “once a decision has been made to transport a patient who is in refractory cardiac arrest, there are prolonged periods during the extrication to the ambulance and en route to the hospital when the quality of CPR is sub-optimal. As the patient is carried down stairs or is transported in an elevator, there is a shift in focus from providing continuous, high-quality CPR to removing the patient from the scene and getting him or her to the hospital quickly and safely. These disruptions in care could have a detrimental effect on patient outcome.”

Limitations and implications

This study, like all studies, comes with plenty of caveats. Most notably — and as the authors themselves point out — this is a retrospective observational study and therefore cannot establish a direct causal relationship between cardiac arrest survival and the floor on which the event took place.

Also, the number of cardiac arrests that occurred on very high floors was small and therefore may have biased the floor-by-floor analysis.

Still, the study raises some issues that residents of high-rise buildings may want to consider — the importance of knowing CPR and how to use an automated external defibrillator (AED), for example.

The study’s authors make the following recommendations to help improve the survival rates of people living in high-rise buildings:

• Give first responders universal access keys so that they have sole access to elevators in emergencies (such as firefighters have during a fire). Currently, first responders often have to wait for elevators to discharge passengers and get to the ground floor before they can take command of it.
• Make sure a building’s staff is alerted to the medical emergency before the first responders arrive so that the responders have clear access to the person in need.
• Increase access to defibrillators in high-rise buildings — and educate residents on how to use them.

FMI: You can download and read the study in full on the CMAJ’s website.