Age-associated time delays in the treatment of acute myocardial infarction with primary percutaneous transluminal coronary angioplasty^B

David C. Lee MD*, Diana M. Pancu MD, Gary S. Rudolph MD, Andrew E. Sama MD

Department of Emergency Medicine, North Shore University Hospital, Manhasset, NY 11030, USA

Received 4 November 2003; accepted 12 December 2003

Abstract Multiple studies have shown that age is a significant factor associated with subOptimal treatment for acute myocardial infarction (AMI). We performed a retrospective pilot study using a chart review of patients who presented with AMI who were subsequently treated with percutaneous transluminal coronary angioplasty (PTCA) from November 1995 to January 1997 at our institution. Ninety-four patients met inclusion criteria, with 5 excluded for insufficient data. Mean time for bdoor-to-balloonQ in all patients was 118 F 48 minutes. The mean patient age was 60 years. Mean times (minutes) for patients grouped by decades of life are as follows: 143 F 59 (30 -39 years), 114 F 51 (40 – 49 years), 99 F 41 (50-59 years), 116 F 44 (60-69 years), 135 F 47 (70 -79 years), and 133 F 133

(80 years and older). Statistical analysis was performed using analysis of variance ( P = 0.04). In this study, age was associated with treatment delays. There was a parabolic relationship of age with time, with a greater time delay occurring in byoungerQ and bolderQ patients.

D 2005

Introduction

To reduce the mortality and morbidity of acute myocar- dial infarction (AMI), a major goal is to rapidly achieve patency of the occluded coronary artery with subsequent reperfusion of the affected myocardiurn. Results of throm- bolytic trials have shown that decreasing the time from onset of symptoms to reperfusion was directly related to improved outcome. This included decreased infarct size, improved left ventricular function, and decreased mortality.

^B This research was presented at the Society for Academic Emergency Medicine annual meeting, Boston, Mass, May 20-23, 1999.

* Corresponding author. Tel.: +1 516 562 1252; fax: +1 516 562 3680.

E-mail address: [email protected] (D.C. Lee).

With the increasing use of primary percutaneous trans- luminal coronary angioplasty (PTCA) for the treatment of AMI, a 60- to 90- minute benchmark (diagnosis to balloon time) to achieve patency of the occluded artery has been suggested. However, a review of the current data from the National Registry of Myocardial Infarction 2 revealed that a Door-to-balloon time of less than 60 minutes is achieved in less than 9% of patients, and greater than 120 minutes in 53% of patients [1,2].

Elderly patients may have even a greater delay to

treatment and reperfusion. Several authors have suggested that older patients, regardless of comorbid conditions, socioeconomic status, and social support undergo less intensive cardiovascular interventions and treatments than do their younger counterparts [3-7]. Survey data show

0735-6757/$ – see front matter D 2005 doi:10.1016/j.ajem.2004.09.026

Age-associated time delays in the treatment of acute myocardial infarction 21

that cardiologists are less likely to administer thrombo- lytics to the elderly as compared with younger patients [8]. Krumholz and colleagues reported in their retrospec- tive study that an 85-year-old patient was 7 times less likely to receive thrombolytic therapy compared with a 55-year-old patient and 10 times less likely to receive PTCA [6]. We hypothesize that elderly patients have a greater delay to PTCA compared with their younger counterparts.

Materials and methods

Design

We performed a retrospective cohort pilot study using a chart review of emergency department (ED) patients who presented with an AMI, as documented by history and standard electrocardiogram criteria, and subsequently treated with primary PTCA over an arbitrary 15-month period (November 1995 to January 1997) at our institution. This protocol was approved by our Institutional Review Board.

Setting

The setting is a suburban, tertiary-care, referral hospital that has an academic ED with an annual census of more than 50,000 patients. At this institution, PTCA is the primary intervention for AMI. Charts of patients were identified by an ongoing standardized interdepartmental quality assurance program, which tracks all patients undergoing cardiac catheterization directly from the ED.

Inclusion criteria

All patients presenting to the ED with AMI who met standard electrocardiogram criteria for thrombolytic therapy and who underwent PTCA were eligible for inclusion.

Exclusion criteria

Patients were excluded if they were transferred to the study hospital from another hospital where the diagnosis of AMI was initially made. Patients were also excluded if they presented to the ED in cardiac arrest secondary to AMI and were not successfully resuscitated in the ED or the catheterization laboratory. All charts were reviewed by a

Fig. 1 Age (y) vs time interval of arrival till angioplasty balloon inf lation (min).

22 D.C. Lee et al.

single physician blinded to study intent. Data was extracted on a standardized collection form that included demographic data, documented time of arrival, and recorded time of inflation of angioplasty balloon.

Statistics

Data were analyzed by analysis of variance. A P value of less than .05 was considered significant.

Results

Ninety-four patients met inclusion criteria, with 5 excluded for insufficient data. The most common reason for insufficient data was unclear time of balloon inflation In this period, no patients received thrombolytic therapy as the primary treatment for AMI in the ED. Mean time for bdoor-to-balloonQ in all patients was 118 F 48 minutes. Mean age was 60 years. Mean times (minutes) were calculated for patients grouped by decades of life: 143 F 59 (30-39 years, n = 5), 114 F 51 (40 – 49 years, n = 15),

99 F 41 (50 -59 years, n = 24), 116 F 44 (60 – 69 years,

n = 22), 135 F 47 (70 -79 years, n = 18), and 133 F 133

(80 years and older, n = 5). Statistical analysis was performed using analysis of variance resulting in a cal- culated P value of .04 (see Fig. 1).

Discussion

Multiple studies have described the deficiencies in the treatment of elderly patients with AMI. Although the cause of this phenomenon is multifactorial, two possible contrib- uting factors are age bias and the lack of outcome studies involving the elderly.

Elderly patients with AMI often present later, have more atypical symptoms, and have a higher mortality and morbidity [2]. Treatment of the elderly has been historically nonaggressive. Earlier thrombolytic trials had excluded the elderly altogether, and as recently as 1990, the American College of Cardiology and American Heart Association designated thrombolytic therapy as a class I agent (therapy usually indicated and effective) only for patients younger than 70 years [9]. Krumholz and colleagues reported that age and Delayed presentation were the top two reasons why thrombolytics were not given as a treatment for AMI although the current literature does not support the exclusion based solely on age [6]. Berger and colleagues reported that elderly patients treated with PTCA have better mortality rates than those treated with thrombolytics [10].

Not surprisingly, our study shows patterns of delay in treatment of AMI. Similar to the studies investigating the use of thrombolytics, elderly patients had a greater delay to treatment. Surprisingly, we also found that younger patients also had significant delays to treatment, Patients younger than 40 years are probably less likely to have atypical

symptoms and extensive comorbidity compared with their elder counterparts. With these two groups of the bextremes of ageQ showing significant delays, we suspect that age bias plays a greater role.

A major limitation to this study is that it was performed at a single site with relatively small numbers. There were large variations in time to treatment within age groups. Younger and older patients had a trend toward delays in treatment but it was difficult to predict the amount of delay for each patient.

More importantly, this study did not evaluate the cause of reported delay. We are uncertain if the delay to treatment is because of a deficiency in our health care, where age bias is the major concern, or to an inherent illness with elderly patients who often present later and have multiple comor- bidities.

Another limitation is that we did not actually study outcome measures. We do not know if this delay was associated with a worse outcome. We assumed that a more rapid time to treatment would equate to an improved outcome. Our results should be validated prospectively and in a larger sample. Future studies should attempt to identify the cause and correct the delays and omissions in treatment.

This would include assessing the impact of age bias in our Clinical decisions.

Although the very elderly (typically described as older than 80 years) is the fastest growing segment of the US population, there are surprisingly few studies of AMI in the very elderly. In our study, although we had a small number of patients in this group (n = 5), they had 33% greater delay in treatment compared with the group with the least delay (age between 50 and 59 years).

Finally, our study implies the need for a large, well- designed, outcome study. The benefit of thrombolytics and PTCA in the elderly and the very elderly still remains controversial. Presently, aggressive treatment with thrombo- lytics or PTCA is recommended, but this is inferred from data extrapolated from a larger literature base of all patients with AMI although many earlier studies had excluded or ignored the elderly or very elderly patients. Future studies measuring outcomes of treatments in the elderly are essential.

In summary, there was an association between age and the door-to-balloon time for patients treated for AMI with PTCA. There was a parabolic relationship of age and time. A greater time delay occurred in byoungerQ and bolderQ patients. These findings suggest that a greater emphasis be placed on reducing time delays for PTCA treatment of AMI, especially for patients in the relative bextremeQ age ranges.

Acknowledgment

This research has been partially funded by the Society for Academic Emergency Medicine Geriatric EMergency med- icine resident/fellow grant sponsored by the American Geriatric Society and the John A Hartford Foundation.

Age-associated time delays in the treatment of acute myocardial infarction 23

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