Circadian variations in acute myocardial infarction: patients or health care delivery?

Percutaneous coronary intervention during on- and off-hours in patients with ST-segment elevation myocardial infarction

OBJECTIVE

There are conflicting data on the clinical outcomes of percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) based on the time of admission to the catheterization laboratory. Thus, we aimed to assess clinical outcomes in an unselected cohort of consecutive patients with STEMI treated with PCI during on-and-off hours of work.

METHODS

A total of 99,783 patients were included in the analysis. Patients were divided using the most frequently used definition: On-hours (Monday-Friday 07:00 AM-04:59 PM); off-hours (Monday-Friday 05:00 PM-06:59 AM, Saturday, Sunday, and nonworking holidays) (37,469 matched pairs). To avoid potential preselection bias, a propensity score was calculated to compare on-and-off hour groups.

RESULTS

Higher radiation doses were observed for PCIs performed during off-hours (1055.2(±1006.5) vs. 1081.6(±1003.25)[mGy] and p = 0.001). A similar prevalence of periprocedural complications was observed during on- and off-hours. However, there was a higher mortality rate during off-hours than during regular working hours (1.17% (439) vs. 1.49% (559) and p = 0.001).

CONCLUSIONS

Primary PCIs in STEMI performed during off-hours might be associated with a higher rate of periprocedural mortality and higher radiation doses than procedures conducted during regular working hours.

Off-hour primary percutaneous coronary angioplasty does not affect outcome of patients with ST-Segment elevation acute myocardial infarction treated within a regional network for reperfusion: The REAL (Registro Regionale Angioplastiche dell'Emilia-Romagna) registry

OBJECTIVES

This study aims to evaluate whether results of "off-hours" and "regular-hours" primary angioplasty (primary percutaneous coronary intervention [pPCI]) are comparable in an unselected population of patients with ST-segment elevation acute myocardial infarction treated within a regional network organization.

BACKGROUND

Conflicting results exist on the outcome of off-hours pPCI.

METHODS

We analyzed in-hospital and 1-year cardiac mortality among 3,072 consecutive ST-segment elevation myocardial infarction (STEMI) patients treated with pPCI between January 1, 2004, and June 30, 2006, during regular-hours (weekdays 8:00 AM to 8:00 PM) and off-hours (weekdays 8:01 PM to 7:59 AM, weekends, and holidays) within the STEMI Network of the Italian Region Emilia-Romagna (28 hospitals: 19 spoke and 9 hub interventional centers).

RESULTS

Fifty-three percent of patients were treated off-hours. Baseline findings were comparable, although regular-hours patients were older and had more incidences of multivessel disease. Median pain-to-balloon (195 min, interquartile range [IQR]: 140 to 285 vs. 186 min, IQR: 130 to 280 min; p = 0.03) and door-to-balloon time (88 min, IQR: 60 to 122 vs. 77 min, IQR: 48 to 116 min; p < 0.0001) were longer for off-hours pPCI. However, unadjusted in-hospital (5.8% off-hours vs. 7.2% regular-hours, p = 0.11) and 1-year cardiac mortality (8.4% off-hours vs. 10.3% regular-hours, p = 0.08) were comparable. At multivariate analysis, off-hours pPCI did not predict an adverse outcome either for the overall population (odds ratio [OR]: 0.70, 95% confidence interval [CI]: 0.49 to 1.01) or for patients directly admitted to the interventional center (OR: 0.79, 95% CI: 0.52 to 1.20).

CONCLUSIONS

When pPCI is performed within an efficient STEMI network focused on reperfusion, the clinical effectiveness of either off-hours or regular-hours pPCI is comparable.

Time of admission, quality of PCI care, and outcome of patients with ST-elevation myocardial infarction

OBJECTIVE

Our study aimed to analyse the hospital mortality of patients admitted in- and off-regular working hours with ST-elevation myocardial infarction (STEMI) within the special logistical setting of the urban area of the city of Berlin.

BACKGROUND

There is a debate whether patients with acute myocardial infarction admitted to hospital outside regular working hours experience higher mortality rates than those admitted within regular working hours.

METHODS

This study analyses data from the Berlin Myocardial Infarction Registry and comprises 2,131 patients with STEMI and treated with percutaneous coronary intervention (PCI) in 2004-2007. Data of patients admitted during in- and off-regular working hours were compared.

RESULTS

There was significant difference in door-to-balloon time (median in-hours: 79 min; median off-hours: 90 min, p < 0.001) and in hospital mortality (in-hours: 4.3%; off-hours: 6.8%, p = 0.020) between STEMI patients admitted in- and off-hours for treatment with PCI. After adjustment, admission off-hours remained an independent predictor for in-hospital death for patients (OR = 2.50; 95% CI 1.38-4.56). In patients with primary care from physician-escorted Emergency Medical Services (EMS), door-to-balloon time was reduced by 10 min for in-hours as well as off-hours patients. The difference in hospital mortality between off-hour and in-hour admission was reduced to a non-significant OR = 1.61 (95% CI 0.79-3.27).

CONCLUSIONS

In conclusion, patients admitted off-hours experienced longer door-to-balloon times and higher hospital mortality than did those admitted in-hours. The differences observed between patients admitted in-hours and off-hours were reduced through physician-escorted EMS reflecting the influence of optimized STEMI care.

Factors associated with poorer prognosis for patients undergoing primary percutaneous coronary intervention during off-hours: biology or systems failure?

OBJECTIVES

We sought to determine whether poorer outcomes in patients undergoing primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (MI) during off-hours are related to delays in treatment, circadian changes in biology, or differences in operator-related quality of care.

BACKGROUND

Previous investigation has suggested that patients undergoing primary PCI during off-hours are more likely to have adverse cardiac events than routine-hours patients, but the reasons for this remain poorly defined.

METHODS

Clinical, angiographic, and procedural characteristics were compared in consecutive patients (n = 685) undergoing primary PCI in the National Heart, Lung, and Blood Institute Dynamic Registry between 1997 and 2006 that were classified as occurring during routine-hours (07:00 to 18:59) or off-hours (19:00 to 06:59). The primary end points were in-hospital death, MI, and target vessel revascularization.

RESULTS

Median time from symptom onset to PCI was similar (off-hours 3.4 h vs. routine-hours 3.3 h). Patients presenting in off-hours were more likely to present with cardiogenic shock and multivessel coronary artery disease but were equally likely to present with complete occlusion of the infarct-related artery. Procedural complications including dissection were more frequent in off-hours patients. In-hospital death, MI, and target vessel revascularization were significantly higher in off-hours patients (adjusted odds ratio [OR]: 2.66, p = 0.001), and differences in outcomes were worse even if the procedure was immediately successful (adjusted OR: 2.58, p = 0.005, adjusting for angiographic success). Patients undergoing PCI on weekends had better outcomes during the daytime than nighttime.

CONCLUSIONS

Patients undergoing primary PCI for acute MI during off-hours are at significantly higher risk for in-hospital death, MI, and target vessel revascularization. These findings appear related to both diurnal differences in presentation and lesion characteristics, as well as differences in procedural complication and success rates that extend beyond differences in symptom-to-balloon time.

Clinical comparison of "normal-hours" vs "off-hours" percutaneous coronary interventions for ST-elevation myocardial infarction

BACKGROUND

High mortality rates were reported in ST-elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary interventions (PPCI) "off-hours." The objective of this study was to evaluate this issue in a more recent population of patients with STEMI treated with PPCI in a high-volume tertiary center specifically dedicated to STEMI treatment.

METHODS AND RESULTS

We analyzed in-hospital/1-year mortality among 985 consecutive patients with STEMI treated with PPCI between January 2003 and December 2005 in a high-volume (>1400 PCI/year) hub center in a STEMI provincial network organization during "normal-hours" (weekdays 08:00 am to 07:29 pm) and "off-hours" (weekdays 07:30 pm to 07:59 am and weekends). Most (61.2%) patients were treated during "off-hours". Clinical and angiographic characteristics of the "normal-hours" and "off-hours" groups were comparable (in both groups, glycoprotein IIb/IIIa were administered to approximately 80% patients). The off-hours group tended toward higher median (25th-75th percentiles) total ischemic time (199 [135-312] minutes vs 179 [126-285] minutes; P = .052). Median electrocardiogram-to-balloon time was less than 90 minutes in both groups. Despite 20 minutes longer median total ischemic time, patients who underwent PPCI during "off-hours" showed similar post-PPCI Thrombolysis In Myocardial Infarction 3 flow grade and mean left ventricular ejection fraction. No difference could be observed between the 2 groups in terms of in-hospital and 1-year mortality rates.

CONCLUSION

This study provides evidence that the clinical effectiveness of "normal" and "off-hours" PPCI can be equivalent, at least when performed at a center specifically dedicated to STEMI treatment with frequent use of glycoprotein IIb/IIIa agents.

The impact of circadian variation on outcomes in emergency acute anterior myocardial infarction percutaneous coronary intervention

OBJECTIVES

We investigated the impact of primary coronary angioplasty performed during night and compared to the impact of that performed during day-time on outcomes of patients with acute ST elevation anterior wall myocardial infarction (AMI).

METHODS

We prospectively followed 273 consecutive patients of whom 160 (58.6%) were treated during day time (8:00 a.m. to 6 p.m.) and 113 (41.4%) were treated "off hours"/at night (6 p.m. to 8 a.m.). Baseline demographics, angiographic factors, and clinical outcomes (death, recurrent AMI, and need for repeat revascularization) were compared between the groups.

RESULTS

Baseline clinical characteristics were similar between the two groups. Unadjusted mortality at one-month was significantly higher among patients who were treated during night compared with those treated at day-time (9.7% vs. 3.1% P = 0.03), as was adverse cardiac event rate (15.9% vs. 6.9%; P = 0.02). Multiple logistic regression analysis adjusted for the CADILLAC risk score demonstrated that this score, which includes baseline LVEF, renal failure, Killip class, final TIMI flow, age>65 years, anemia, and the number of coronary vessel diseases, is a significant predictor of one-month mortality, while the effect of time of treatment was borderline (night vs. day; odds ratio 2.7; 95% confidence interval, 0.8-9.4; P = 0.095).

CONCLUSIONS

The results of this study indicate that patients with anterior myocardial infarction treated during night time have worse unadjusted short-term clinical outcomes despite no delay from onset of symptoms to actual treatment. Larger studies are needed in order to identify potential contributors to this phenomenon.

Temporal variation in inhospital mortality with percutaneous coronary intervention: a report from the National Heart, Lung and Blood Institute Dynamic Registry

BACKGROUND

Cardiovascular morbidity and mortality display a distinct time dependence also known as circadian variation. Whether such time dependence extends to the risk of procedural-related mortality after percutaneous coronary intervention (PCI) is presently unknown.

METHODS

Inhospital mortality was analyzed in 6,347 patients with PCI start times from 8:00 am to 6:59 pm ("usual" workday). The sample was divided into 3 evenly populated groups (morning start 8:00-10:59 AM, midday start 11:00 AM-1:59 PM, afternoon start 2:00-6:59 PM). The association between procedural start time and mortality was assessed using multivariable analysis including a propensity score accounting for factors associated with procedural start time.

RESULTS

There was a significant, nonlinear relationship between procedural-related mortality and start time (P = .03). Afternoon start patients were at higher adjusted risk of mortality compared with midday start patients (OR 2.03, 95% CI 1.07-3.83, P = .03 ). Morning start patients were also at higher risk compared with midday start patients although the association was not statistically significant (OR 1.73, 95% CI 0.89-3.39, P = .11).

CONCLUSIONS

There is a significant time-dependent variation in the risk of inhospital PCI-related mortality during usual working hours. The highest risk period, taking into account numerous factors that confound this association, is the latter part of the workday. A second period of apparent greater risk occurs during the early part of the workday and is consistent with our present understanding of circadian variation in cardiovascular disease processes.

Facilitated primary coronary intervention with abciximab and very low dose of alteplase during off-hours compared with direct primary intervention during regular hours

In patients with acute myocardial infarction (AMI), the off-hour presentation is one of the major determinants of door-to-balloon delay. Moreover, the nighttime presentation is associated with increased mortality after primary coronary intervention (PCI). The prompt starting of a therapy able to start recanalization of the infarct-related artery before intervention might improve the results of off-hour primary PCI. We compared the outcome of 212 consecutive patients with AMI undergoing either direct or facilitated PCI according to the hour of presentation. Patients arriving off-hours were pretreated with alteplase (20 mg) and abciximab and underwent facilitated PCI. Patients presenting on-hours underwent direct PCI. A basal Thrombolysis in Myocardial Infarction (TIMI) flow grade 3 was observed in 1.0% of patients undergoing direct PCI and in 44% of patients undergoing facilitated PCI (P = 0.001). More patients starting PCI with a TIMI 3 flow achieved a postinterventional fast TIMI frame count (72.0% vs. 38.8% direct PCI group vs. 34.9% facilitated PCI group with basal TIMI 0-2; P = 0.001) and a TIMI perfusion grade 3 (66.0% vs. 38.8% direct PCI group vs. 39.7% facilitated PCI group with basal TIMI 0-2; P = 0.004). Preinterventional TIMI flow grade 3 was associated with a higher gain in left ventricular ejection fraction at 1 month (10.9% +/- 6.4% vs. 7.0% +/- 9.6% direct PCI group vs. 6.1% +/- 6.0% facilitated PCI group with basal TIMI 0-2; P = 0.005). No significant difference was observed in major bleedings, although there was a trend toward a higher risk in the facilitated PCI group. Patients in the facilitated PCI group achieving a basal TIMI 3 flow showed improved myocardial reperfusion and better left ventricular function recovery. Bleeding complications associated with combination therapy remained an important concern.