Author + information
- Atman P. Shah, MD and
- William J. French, MD⁎ ()
- ↵⁎Reprint requests and correspondence:
Dr. William J. French, Harbor-UCLA Medical Center, 1000 W. Carson Street, Torrance, California 90502-2004
- percutaneous coronary intervention
- ST-segment elevation myocardial infarction
- acute myocardial infarction
Primary percutaneous coronary intervention (PPCI) by experienced operators is widely considered optimal treatment of an acute ST-segment elevation myocardial infarction (STEMI). Recent efforts have focused on expanding access to PPCI, decreasing time-to-treatment, and improving outcomes.
However, achieving favorable results 24 h a day, 7 days a week has been elusive and difficult. Previous studies have reported that patients who presented with a STEMI during off-hours have had prolonged door-to-balloon times and subsequently higher mortality (1). This conclusion has led interventionalist cardiologists to believe that there is something particularly nefarious about patients presenting at night with a STEMI.
In this issue of JACC: Cardiovascular Interventions, Glaser et al. (2) report good news from their study of a large registry of STEMI patients studied between 1997 and 2006. Glaser et al. (2) determined that outcomes were similar during daylight hours for PPCI whether during the weekday or the weekend. The bad news, however, was that patients who presented with STEMI and were treated with PPCI during off-hours had a poorer prognosis than those who presented during the daytime.
They report that patients who presented at night from 7:00 pm to 6:59 am had a greater incidence of death, myocardial infarction, and target revascularization than those who arrived during daylight hours during either a weekday or weekend. This data again supports a nighttime PPCI related jinx. This jinx may not be relegated only to interventional cardiologists, as evidenced by a recent study (3) that reported that patients who received renal transplants at night had increased risks of acute rejection and other complications than did daytime transplant recipients.
Various theories have hypothesized that patients who present at night are sicker because they may be sleeping through their symptoms. Another hypothesis is that variations in the circadian rhythm result in a higher degree of plaque vulnerability at night (4). There could also be a socioeconomic component, whereby working Americans without health insurance are more likely to present at nighttime so as to avoid missing a day of work.
A review of the baseline clinical characteristics in the study by Glaser et al. (2) reveals that the patients who presented during off-hours were more likely to be Black, have multivessel disease, or cardiogenic shock. It is known that Black patients presenting with acute myocardial infarction have a higher mortality than White patients (5) and that multivessel coronary artery disease and cardiogenic shock are also clinical predictors that portend a poor outcome (6).
There are some limitations of this study that may weaken the conclusions of Glaser et al. First, despite the fact that the registry included patients from 1996 to 2007, only 685 patients were studied, a much smaller cohort than was reported by Magid et al. (1) in a study of the National Registry of Myocardial Infarction database. Furthermore, if arriving in the middle of the night with a STEMI confers a poor prognosis because of the disease process; this poor prognosis should be noticed not only in patients treated with PCI but possibly also in those treated with fibrinolytic therapy, but this data was not reported. Finally, the study reports a “symptom to PCI time,” not a traditional door-to-balloon time. Knowing the door-to-balloon time may be helpful in determining if hospitals have adequate processes in place to identify, triage, and treat STEMI patients.
The most concerning conclusion of Glaser et al.'s study is the potential role of physician error during off-hours. Although the interventional cardiologist cannot control for all of the baseline characteristics of the patients, there is troubling data in this study that points to physician fatigue resulting in poorer outcomes. First, only 76% of off-hours patients received stents compared with 82.4% of those presenting during the daytime. Moreover, 16.3% of off-hours patients were treated solely with balloon angioplasty compared with only 12.8% of daytime patients. Why were the sicker off-hours patients more often treated with balloons and less often with coronary stents? The benefit of stents over coronary angioplasty has been well described and is the standard of care (7,8).
Second, fewer adjunctive devices such as intravascular ultrasound (IVUS) and mechanical thrombectomy were used during PCI. The use of IVUS during STEMI may facilitate stent sizing that may reduce stent thrombosis. Although this theory has not been proven, the fact that 4.6% of patients during the daytime received IVUS but only 0.8% during the off-hours suggests that IVUS had an important role in PPCI in the institutions participating in the study. Physicians at night simply used IVUS less often.
In addition, off-hours patients were almost 5 times less likely than their daytime counterparts to receive mechanical thrombectomy, a technique that has been associated with improved reperfusion (9). These findings suggest that patients presenting during the off-hours were not receiving the same care as those during the daytime. The finding that off-hours patients were less likely to receive pre-procedure thienopyridines provides further evidence for this.
Third, there were more complications in the off-hours group, specifically in the form of major dissections, possibly related to operator performance. The investigators astutely point out that the incidence of distal embolization, a complication resulting from lesion characteristics, was no different between the 2 groups.
Finally, and most concerning, is the operator's reaction to the unsuccessful PCI during the off-hours (Thrombolysis In Myocardial Infarction flow grade 3: 87.5% during off-hours vs. 92.9% during daytime). The study (2) notes that after unsuccessful off-hours PCI, physicians reported that “the lesion was treated successfully but did not respond appropriately.” Certainly, a lesion in the coronary artery may manifest certain biophysical properties, but anthropomorphizing a lesion is not an action that will lead to improvements in patient care.
Physicians treating patients at night used fewer stents and employed fewer adjunctive therapies than if the patients had presented during daytime hours. Procedures were less successful at night and physicians attributed failures to lesion characteristics. It is human nature to want to be efficient in the middle of the night, especially with a family at home and a full day of work ahead. What if the desire to move quickly results in poorer patient outcomes?
Sleep deprivation has long been known to result in poor cognitive performance. A recent report (10) studied the effects on the psychomotor and cognitive skills of on-call surgical residents. The study concluded that fatigue and sleep deprivation resulted in a significant deterioration of psychomotor skills as well as an increase in cognitive errors (memory, attention, and intermodal coordination tasks), tasks specifically needed by the interventional cardiologist performing PPCI (10). A previous study associated the abnormal neurobehavioral performance of residents after night call with a blood alcohol level of 0.04% to 0.05% (11).
Expecting physicians to perform at their full capabilities in the middle of the night after having put in a 12-h day taking care of patients is a hopeful, but probably unrealistic, expectation. In addition, the next morning will bring an entire host of patients and cases that the physician needs to address. As this study (11) elegantly shows, a tired physician may make errors in judgment during cases leading to increased mortality, an end point every physician hopes to avoid.
All is not hopeless however, for there are several avenues to improve the situation. But these potential solutions will require a change from current practice.
First of all, only board-certified interventional cardiologists who meet the American College of Cardiology/American Heart Association/Society for Cardiac Angiography and Interventions guidelines of performing at least 75 PCIs per year at a hospital that performs over 200 PCIs a year (including >36 STEMIs) (12) should take night calls. If the off-hours cases truly are a different, more difficult cohort of cases, only the best-trained and most qualified physicians should treat those patients.
This mandate may have other important implications for creating more specialized STEMI receiving centers (SRCs) (13). The SRC, designed on the trauma center model, allows emergency medical services to bypass non-PCI hospitals and bring STEMI patients to the nearest SRC facility that is required to have interventional cardiologists, bypass surgeons, and a qualified cardiac catheterization laboratory staff and equipment available 24 h a day, 7 days a week.
Second, interventionalists should not be on call for more than 2 nights in a row. If a physician's neurocognitive abilities are hampered on the first night on call, it is not a great leap of faith that these abilities will be severely strained on the second night. If a physician has to be on call for 2 nights in a row, some researchers have suggested that reducing daytime clinical duties or even taking a nap before the overnight shift may improve performance (14).
Third, despite the likelihood of widespread resistance, the time may have come for in-house interventionalists who work in shifts. Many municipalities in the U.S. have implemented systems that transport STEMI patients to designated SRC hospitals. These large hospitals with capable operators and on-site cardiothoracic surgery are probably better equipped to handle high-risk STEMI patients. One option is to have different hospitals be “on call” each night. Another option is to have an in-house interventionalist, the ultimate hospitalist, available who may improve outcomes by shortening the door-to-balloon time. Interventionalists who work a series of 12-h shifts would be immune from the daily barrage of patient care and administrative duties. They would be able to focus solely on taking care of the sickest patients who are transported to their institution. Granted, not every hospital will be able to support this model, but the ones that do may represent the future direction of having a small number of PCI referral centers in any given metropolitan area, similar to the model of having a select few, highly capable trauma centers.
This study highlights the fact that in the setting of primary PCI, a short door-to-balloon time is not the only process that can improve patient outcomes. The federal government mandates work hours restrictions for pilots and truck drivers. How about for the interventional cardiologist? Can restrictions, either self-imposed or otherwise, be far behind?
↵⁎ Editorials published in JACC: Cardiovascular Interventions reflect the views of the authors and do not necessarily represent the views of JACC: Cardiovascular Interventions or the American College of Cardiology.
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