口袋女优

Rapid transport of high-risk heart attack patients to the cath lab is achievable, but nonsystem delays, such as patient comorbidities, still hinder timely reperfusion, data from a large registry showed.

Nonsystem delays were common, occurring in nearly 15% of patients and resulting in a 15% in-hospital mortality rate compared with 2.5% in those with no delay (P<0.0001), according to Rajesh V. Swaminathan, MD, of Weill Cornell Medical College in New York City, and colleagues.

The highest in-hospital mortality rate (30%) was attributed to those patients who, in conjunction with receiving primary percutaneous coronary intervention (PCI), suffered a cardiac arrest and needed intubation, they reported in an early online publication of the April 23 issue of the Journal of the American College of Cardiology.

The patients in this study all were high risk, presenting with an ST-segment elevation MI (STEMI).

Each category of nonsystem delay was associated with significantly increased mortality as compared with patients whose door-to-balloon time (D2BT) was not delayed (P<0.0001).

Rates of other patient-related factors that delayed reperfusion of the culprit lesions and their associated in-hospital mortality rates were:

• Delayed consent -- 4.4%, with a 9.4% mortality rate
• Difficult vascular access -- 8.4%, with an 8% mortality rate
• Difficulty crossing culprit lesion -- 18.8%, with a 5.6% mortality rate
• Other factors -- 31%, with a 5.9% mortality rate

Even though nonsystem factors delayed the time to device deployment, 47% of the patients with nonsystem delays had a D2BT under 90 minutes, the national benchmark.

Though important, the results can be deceiving, according to the authors of an accompanying editorial.

"Clearly, one would not expect a 6-fold difference in mortality with only a 30-minute difference in the median D2BTs," wrote Cindy Grines, MD, and Theodore Schreiber, MD, of Detroit Medical Center.

"The importance of this study is that it demonstrates that delay, in and of itself, is probably not responsible for huge differences in mortality," they added. "It is likely a marker for higher-risk patients, and the extent of risk is difficult to ascertain in retrospective studies."

Harlan Krumholz, MD, of Yale University School of Public Health, who was not involved in the study, noted that many factors are involved in achieving a timely reperfusion.

“Many of these nonsystem delays might be amenable to improved systems," Krumholz said in an interview. “The delays in getting consent,” for example, “might be because we’re not set up well enough to get consent rapidly.”

He said facilities should enact protocols that allow the swift collection and/or dissemination of information.

Most studies of delays in D2BT have focused on system-related factors, such as need for transfer, nondaytime arrival at a hospital, low procedural volume, and demographic factors such as older age, female sex, and nonwhite race. In contrast, limited information has accumulated regarding nonsystem contributors to delayed D2BT.

To inform on effects of nonsystem factors that delay D2BT, Swaminathan and colleagues searched the national CathPCI Registry and identified patients with STEMI lesions treated at registry hospitals from Jan. 1, 2009 through June 30, 2011.

For their analysis, they excluded patients seen more than 12 hours after symptom onset, transferred patients, those who received thrombolytic therapy, and patients treated at low-volume centers.

The final analysis comprised 82,678 patients. The median D2BT was 65 minutes, and 18.9% of patients had a D2BT greater than 90 minutes.

Investigators identified nonsystem delays in 12,146 (14.7%) cases, which were associated with a median D2BT of 92 minutes versus 63 minutes for patients without nonsystem delays.

In general, nonsystem delays were associated with older age, female sex, African-American race, and presence of one or more comorbidities.

Delayed consent led in the longest delays in D2BT (median 100 minutes) and resulted in patients missing the 90-minute goal in 67% of cases. Cardiac arrest/intubation was associated with the shortest delay (median D2BT of 84 minutes).

The study had some limitations including its retrospective nature, potential unmeasured confounding, heterogeneous mixture of facilities, and having no reason for a third of nonsystem delays, researchers wrote.

From the American Heart Association:

Comment