Highlights
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In STEMI, the time from symptoms to interventional treatment is defined as pain-to-balloon time
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Rising pain-to-balloon times are associated with increased 1-year mortality
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The major delay is caused by time from pain onset until hospital arrival
Limited and inconsistent data are present regarding the importance of the time delay between symptom onset and balloon inflation in ST-segment elevation myocardial infarction (STEMI) patients. We aimed to investigate the possible influence of prolonging pain-to-balloon times (PBT) on in-hospital outcomes and mortality in a large cohort of patients with STEMI undergoing primary percutaneous coronary intervention. We retrospectively studied 2,345 STEMI patients (age 61 ± 13 years, 82% men) who underwent primary percutaneous coronary intervention. Patients were stratified according to PBT into 3 groups: ≤120 minutes, 121 to 360 minutes, and >360 minutes. Patients’ records were assessed for the occurrence of in-hospital complications, 30-day, and 1-year mortality. Of the 2,345 study patients, 36% had PBT time ≤120 minutes, 40% had PBT of 121 to 360 minutes and 24% had PBT time >360 minutes. The major part of the total PBT (average 358 minutes) was caused by the time interval from symptom onset to hospital arrival, namely, pain-to-door time (average 312 minutes) in all 3 groups. Longer PBT was associated with a lower left ventricular ejection fraction, higher incidence of in-hospital complications, and higher 30-day mortality. In 2 multivariate cox regression models, a per-hour increase in PBT (hazard ratio 1.03 [95% confidence interval 1.00 to 1.06], p = 0.039) as well as PBT >360 minutes (hazard ratio 1.6 [95% confidence interval 1.1 to 2.5], p = 0.04) were both independently associated with an increased risk for 1-year mortality. In conclusion, PBT may be an accurate and independent marker for adverse events, pointing to the importance of coronary reperfusion as early as possible based on the onset of pain.
Early reperfusion with primary percutaneous coronary intervention (PCI) is currently the recommended first choice treatment strategy for patients presenting with ST-segment elevation myocardial infarction (STEMI). Studies showed a direct relationship between the duration of coronary occlusion and ischemic myocardial cell injury, with longer time to treatment intervals resulting in higher mortality. Door-to-balloon time (DBT), defined as the interval from arrival at the hospital until inflation of the balloon to restore flow in the occluded artery, emerged as a key quality indicator for hospital performance , and both American and European guidelines focus recommendations on shortening DBT. , Although a clear relation has been demonstrated between mortality and time delay from symptom onset to treatment in STEMI patients receiving thrombolysis, only limited and inconsistent results are present regarding the effect on clinical outcomes in STEMI patients undergoing primary PCI. We aimed to investigate the influence of prolonged time intervals from symptom onset to balloon inflation on outcomes and mortality in a large cohort of STEMI patients treated by primary PCI.
Methods
A retrospective, single-center observational study was performed at the Tel-Aviv Sourasky Medical Center, a tertiary referral hospital with a 24/7 primary PCI service. Included were 2,586 patients, admitted between 2007 and 2019 with the diagnosis of acute STEMI and subsequently treated with primary PCI. We excluded patients transferred from other hospitals (n = 32) and patients in whom no documentation of any of the relevant time intervals was found in the medical records (n = 209). The final study population included 2,345 STEMI patients. Diagnosis of STEMI was established following published guidelines including typical chest pain history, diagnostic electrocardiographic changes, and serial elevation of cardiac biomarkers. Primary PCI was performed in patients with symptoms ≤12 hours in duration as well as in patients with symptoms lasting 12 to 24 hours if pain consisted at the time of admission.
Pain-to-door time (PDT) was defined as the time from symptom onset (usually chest pain or discomfort) to hospital admission (either to the emergency room or directly to the catheterization laboratory) as documented in the patient’s medical records. DBT was defined as the time interval between a patient’s arrival at the hospital and the first balloon inflation or device deployment in the culprit artery as taken from the computerized patient file. Pain-to-balloon time (PBT) was defined as the sum of PDT and DBT time. To evaluate differences in patient characteristics and outcomes we stratified patients into 3 groups based on PBT: ≤120 minutes and 121 to 360 minutes and >360 minutes.
Baseline demographics, cardiovascular history, clinical risk factors, laboratory results, coronary findings during PCI, and echocardiographic measurements were all retrieved from the hospital’s electronic medical records. Patient records were then evaluated for in-hospital mortality and complications occurring during hospitalization. These included heart failure episodes treated conservatively, cardiogenic shock (defined as the need for cardiac inotropes or the need for intra-aortic balloon counterpulsation insertion), mechanical ventilation, and clinically significant tachyarrhythmias. Assessment of survival following hospital discharge was determined from computerized records of the population registry bureau.
Written informed consent was obtained from all individuals included in the study. The study protocol conforms to the ethical guidelines of the 1975 Declaration of Helsinki as reflected in a priori approval by the institution’s human research committee (TLVMC IRB 16 to 224).
Continuous variables were presented as mean and standard deviation and compared with one-way analysis of variance (ANOVA). Categorical variables are presented as percentages; p values were calculated with the chi-square test. Survival rates were described by the Kaplan-Meier method. Independent predictors of 1-year mortality were determined in a multivariate cox regression model adjusted for all baseline variables found to be significant in univariate analysis. A 2-tailed p value of <0.05 was considered significant for all analyses. All analyses were performed with SPSS Statistics for Windows Version XX (SPSS Inc., Chicago, Illinois, version 25).
Results
The study population included 2,345 STEMI patients (mean age 61 SD 13 years, 82% men). Of these, 853 patients (36%) had PBT ≤120 min, 926 (40%) had PBT of 121 to 360 minutes and 566 (24%) had PBT >360 minutes. Table 1 lists the baseline characteristics of patients according to the 3 PBT groups. There was a graded increase in both PDT and DBT times within the 3 groups, however, mean DBTs were still <90 minutes for all groups. Table 2 lists the procedural outcomes and in-hospital complications according to the PBT groups. Patients with longer PBT had a lower postprocedural left ventricular ejection fraction and were more likely to develop acute kidney injury, heart failure episodes, or cardiogenic shock. Longer PBT was associated with a higher 30-day mortality (1.8% vs 2.9% vs 4.2%, p = 0.03).
| Pain-to-Balloon Time (Minutes) | ||||
|---|---|---|---|---|
| Variable | ≤120 (n = 853) | 121-360 (n = 926) | >360 (n = 566) | p Value |
| Age (years), mean±SD | 59±12 | 62±13 | 63±14 | <0.001 |
| Men | 735(86%) | 740(80%) | 442 (78%) | <0.001 |
| Hypertension | 329(39%) | 416(45%) | 278(49%) | <0.001 |
| Diabetes mellitus | 163(19%) | 206(22%) | 163(29%) | <0.001 |
| Family history of CAD | 181(21%) | 219(24%) | 99(18%) | 0.02 |
| Chronic kidney disease | 186(22%) | 205(22%) | 149(26%) | 0.10 |
| Past myocardial infarction | 125(15%) | 115(12%) | 63(11%) | 0.13 |
| Smoker | 436(51%) | 482(52%) | 272(48%) | 0.31 |
| Hyperlipidemia | 405(48%) | 441(48%) | 280(49%) | 0.73 |
| Number of coronaries narrowed | 0.04 | |||
| 1 | 394(46%) | 389(42%) | 228(40%) | |
| 2 | 257(30%) | 286(31%) | 164(29%) | |
| 3 | 202(24%) | 251(27%) | 174(31%) | |
| Pain-to-door time(min), mean±SD | 57±17 | 153±62 | 954±431 | <0.001 |
| Door-to-balloon time (min), mean±SD | 36±14 | 49±23 | 54±27 | <0.001 |
| Pain-to-Balloon Time (Minutes) | ||||
|---|---|---|---|---|
| Variable | <120 min (n = 853) | 121–360 min (n = 926) | >360 min (n = 566) | p Value |
| LVEF (%), mean±SD | 48±8 | 47±8 | 46±8 | <0.001 |
| LVEF≤45% | 388(46%) | 462(51%) | 312(56%) | 0.001 |
| Acute kidney injury | 60(7%) | 71(8%) | 74(13%) | <0.001 |
| Heart failure | 76(9%) | 71(8%) | 67(12%) | 0.02 |
| VT\VF | 101(12%) | 56(6%) | 30(5%) | <0.001 |
| Mechanical ventilation | 43(5.0%) | 33(3.6%) | 26(4.6%) | 0.29 |
| Cardiogenic shock | 29(3.4%) | 31(3.3%) | 31(5.5%) | 0.08 |
| 30- day mortality | 16(1.9%) | 27(2.9%) | 24(4.2%) | 0.03 |
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