Differences between sexes in STEMI treatment and outcomes with contemporary primary PCI.

BACKGROUND: Historically, differences in timely reperfusion and outcomes have been described in females who suffer ST-segment elevation myocardial infarction (STEMI). However, there have been improvements in the treatment of STEMI patients with contemporary Percutaneous Coronary Intervention (PCI) strategies. METHODS: Comparisons between sexes were performed on STEMI patients treated with primary PCI over a 4-year period (January 1, 2017-December 31, 2020) from the Queensland Cardiac Outcomes Registry. Primary outcomes were 30-day and 1-year cardiovascular mortality. Secondary outcomes were STEMI performance measures. The total and direct effects of gender on mortality outcomes were estimated using logistic and multinomial logistic regression models. RESULTS: Overall, 2747 (76% male) were included. Females were on average older (65.9 vs. 61.9 years; p < 0.001), had longer total ischemic time (69 min vs. 52 min; p < 0.001) and less achievement of STEMI performance targets (<90 min) (50% vs. 58%; p < 0.001). There was no evidence for a total (odds ratio [OR] 1.3 (95% confidence interval [CI]: 0.8-2.2; p = 0.35) or direct (adjusted OR 1.2 (95% CI: 0.7-2.1; p = 0.58) effect of female sex on 30-day mortality. One-year mortality was higher in females (6.9% vs. 4.4%; p = 0.014) with total effect estimates consistent with increased risk of cardiovascular mortality (Incidence rate ratio [IRR]: 1.5; 95% CI: 1.0-2.3; p = 0.059) and noncardiovascular mortality (IRR: 2.1; 95% CI: 0.9-4.7; p = 0.077) in females. However, direct (adjusted) effect estimates of cardiovascular mortality (IRR: 1.0; 95% CI: 0.6-1.6; p = 0.94) indicated sex differences were explained by confounders and mediators. CONCLUSION: Small sex differences in STEMI performance measures still exist; however, with contemporary primary PCI strategies, sex is not associated with cardiovascular mortality at 30 days or 1 year.

Patient preferences for heart valve disease intervention.

BACKGROUND: This study aimed to determine how patients trade-off the benefits and risks of two different types of procedures used to treat heart valve disease (HVD). It also aimed to determine patients' preferences for HVD treatments (predicted uptake) and the relative importance of each treatment attribute. METHODS: A discrete choice experiment (DCE) was conducted in Australia and Japan with patients who required a heart valve procedure. Patients were stratified into three categories: no prior procedure experience, minimally invasive procedure experience and invasive procedure experience. DCE attributes included risk of mortality; risk of stroke; needing dialysis; needing a new pacemaker; valve durability; independence 1 month after surgery; and out-of-pocket expenses. Participants chose between two hypothetical labelled approaches to therapy ('invasive procedure' and 'minimally invasive procedure'), with a separate opt-out included. A mixed multinomial logit model was used to analyse preferences. RESULTS: The DCE was completed by 143 Australian and 206 Japanese patients. Both populations demonstrated an overall preference for the minimally invasive procedure over the invasive procedure. All attributes tested significantly predicted choice and were important to patient decision-making. However, patients' choices were most influenced by the durability of the valve and the likelihood of independence postprocedure, irrespective of their prior procedure experience. Differences in preference were observed between Australian and Japanese patients; valve durability was the most important attribute among Australian patients, while Japanese patients emphasised regaining independence postsurgery. Risk of mortality was less important relative to other key attributes in Japan; however, it remained significant to the model. CONCLUSIONS: HVD patients prefer a minimally invasive procedure over an invasive procedure, irrespective of prior treatment experience. Key attributes contributing to treatment preferences are valve durability and faster recovery. These results can be used to help inform healthcare decision-makers about what features of heart valve procedures patients value most. PATIENT AND PUBLIC CONTRIBUTION: People with lived experience of HVD were included in multiple stages of the design phase of this research. First, patients and doctors were consulted by taking part in qualitative interviews. The qualitative interviews helped inform which treatment attributes to include in the DCE based on what was important to those with lived experience and those who help make treatment decisions on behalf of patients. Qualitative interview participants also assisted with the framing of questions in the online survey to ensure the terminology was patient-friendly and relevant to those with lived experience. Following qualitative interviews, the DCE attribute list was agreed on in expert consultation with a steering committee, which included patient representatives and treating physicians (interventional cardiologists, cardiothoracic surgeons). The survey was also pilot tested with a small sample of patients and minor adjustments were made to the wording to ensure it was appropriate and meaningful to those with lived experience of HVD.

Sex differences in time to primary percutaneous coronary intervention and outcomes in patients presenting with ST-segment elevation myocardial infarction.

OBJECTIVES: We assessed sex differences in treatment and outcomes in ST-segment elevation myocardial infarction (STEMI) patients treated with primary percutaneous coronary intervention (PCI). BACKGROUND: Historically, delays to timely reperfusion and poorer outcomes have been described in women who suffer STEMI. However, whether these sex discrepancies still exist with contemporary STEMI treatment remains to be evaluated. METHODS: Consecutive STEMI patients treated with primary PCI patients over a 10-year period (January 1, 2010 to December 31, 2019) from a tertiary referral center were assessed. Comparisons were performed between patient's sex. Primary outcomes were 30-day and 1-year mortality. Secondary outcomes were STEMI performance measures. RESULTS: Most patients (n = 950; 76%) were male. Females were on average older (66.8 vs. 61.4 years males; p < 0.001). Prehospital treatment delays did not differ between sexes (54 min [IQR: 44-65] females vs. 52 min [IQR: 43-62] males; p = 0.061). STEMI performance measures (door-to-balloon, first medical contact-to-balloon [FMCTB]) differed significantly with longer median durations in females and fewer females achieving FMCTB < 90 min (28% females vs. 39% males; p < 0.001). Women also experienced greater rates of initial radial arterial access failure (11.3% vs. 3.1%; p < 0.001). However, there were no significant sex differences in crude or adjusted mortality between sexes at 30-days (3.6% male vs. 5.1% female; p = 0.241, adjusted OR: 1.1, 95% CI: 0.5-2.2, p = 0.82) or at 1-year (4.8% male vs. 6.8% female; p = 0.190, adjusted OR: 1.0, (95% CI: 0.5-1.8; p = 0.96). CONCLUSION: Small discrepancies between sexes in measures of timely reperfusion for STEMI still exist. No significant sex differences were observed in either 30-day or 1-year mortality.

Impact of Patient BMI on Patient and Operator Radiation Dose During Percutaneous Coronary Intervention.

AIMS: This study sought to investigate patient and operator radiation dose in patients undergoing percutaneous coronary intervention (PCI) and the impact of body mass index (BMI) on patient and operator dose. METHODS: In patients undergoing PCI, radiation dose parameters, baseline characteristics and procedural data were collected in a tertiary centre for 3.5 years. Operators wore real time dosimeters. Patients were grouped by BMI. Dose area product (DAP) and operator radiation dose were compared across patient BMI categories. Multivariable analysis was performed to investigate the impact of patient BMI and other procedural variables on patient and operator dose. RESULTS: 2,043 patients underwent 2,197 PCI procedures. Each five-unit increase in BMI increased patient dose (expressed as DAP) by an average 31% (95% CI: 29-33%) and operator dose by 27% (95% CI: 20-33%). Patient dose was 2.3 times higher and operator dose was 2.4 times higher in patients with a BMI>40 than for normal BMI patients. Multivariable analysis indicated that there were many procedural factors that were predictors for increasing operator dose and patient dose but that patient BMI was a major contributor for both operator dose and patient dose. CONCLUSION: Increasing BMI increases the DAP and operator dose for PCI procedures and BMI is demonstrated to be a major factor that contributes to both patient and operator radiation dose.

Clinical Outcomes in Pre-Hospital Activation and Direct Cardiac Catheterisation Laboratory Transfer of STEMI for Primary PCI.

INTRODUCTION: Pre-hospital activation and direct cardiac catheterisation laboratory (CCL) transfer of ST segment elevation myocardial infarction (STEMI) has previously been shown to improve door-to-balloon (DTB) times yet there is limited outcome data in the Australian context. We aimed to assess the impact of pre-hospital activation on STEMI performance measures and mortality. METHODS: Prospective cohort study of consecutive ambulance transported STEMI patients treated with primary percutaneous coronary intervention (PCI) patients over a 10-year period (1 January 2008-31 December 2017) at The Prince Charles Hospital, a large quaternary referral centre in Brisbane, Queensland Australia. Comparisons were performed between patients who underwent pre-hospital CCL activation and patients who did not. STEMI performance measures, 30-day and 1-year mortality were examined. RESULTS: Amongst 1,009 patients included (mean age: 62.8 yrs±12.6), pre-hospital activation increased over time (26.6% in 2008 to 75.0% in 2017, p<0.001). Median DTB time (35 mins vs 76 mins p<0.001) and percentage meeting targets (DTB<60 mins 92% vs 27%, p<0.001) improved significantly with pre-hospital activation. Pre-hospital activation was associated with significantly lower 30-day (1.0% vs 3.5%, p=0.007) and 1-year (1.2% vs 7.7%, p<0.001) mortality. After adjusting for confounders and mediators, we observed a strong total effect of pre-hospital activation on 1-year mortality (OR 5.3, 95%CI 2.2-12.4, p<0.001) compared to patients who did not have pre-hospital activation. False positive rates were 3.7% with pre-hospital activation. CONCLUSION: In patients who underwent primary PCI for STEMI, pre-hospital activation and direct CCL transfer is associated with low false positive rates, significantly reduced time to reperfusion and lower 30-day and 1-year mortality.

Transcatheter aortic valve-in-valve implantation for failed surgical bioprosthetic valves. A minimalist approach without contrast aortography or echocardiographic guidance.

OBJECTIVES: To demonstrate safety, feasibility and short-term clinical outcomes after transcatheter aortic valve-in-valve (ViV) implantation under local anesthesia without contrast aortography or echocardiographic guidance. BACKGROUND: Transcatheter ViV implantation is an emerging treatment modality for patients with degenerative surgical bioprostheses. Given the radiopaque properties of the surgical aortic valve (SAV) frame, ViV procedures can often be performed with fluoroscopic guidance alone. METHODS: ViV implantation was performed in 37 patients with SAV failure under local anesthesia without contrast aortography. Clinical and echocardiographic data were obtained at baseline, discharge, and 30 days. RESULTS: Mean age was 74 ± 10 years and STS predicted risk of mortality was 5.6 ± 2.4%. Mean transaortic gradient decreased from 39.4 ± 15.5 mmHg to 13 ± 6.3 mmHg at discharge (p < .001), and 20 ± 7.5 mmHg at 30 days (p < .001 compared to baseline), aortic valve area increased from 0.9 ± 0.3 cm2 to 1.2 ± 0.4 cm2 at 30 days (p = .007). No patient had more than mild aortic regurgitation. Hospital discharge occurred at a median of 2.6 ± 4.4 days. At 30-day follow-up there were no deaths, myocardial infarctions, strokes, repeat hospital admissions for heart failure, or renal failure. One patient (2.7%) required a new pacemaker. 93% of the patients were in New York Heart Association functional class I or II. CONCLUSIONS: Transcatheter aortic ViV implantation for selected patients with degenerative surgical bioprostheses under local anesthesia without aortography or echocardiographic guidance is feasible and safe.

Mid-term outcome in patients with bicuspid aortic valve stenosis following transcatheter aortic valve replacement with a current generation device: A multicenter study.

OBJECTIVES: To perform clinical and echocardiographic follow-up beyond 1 year in consecutive patients with severe bicuspid aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR) with a current generation balloon-expandable valve. BACKGROUND: Treatment of bicuspid aortic valve disease with TAVR remains controversial and late follow-up data is still scarce. METHODS: We collected baseline characteristics, procedural data, 30-day and mid-term clinical follow-up findings from six centers in Europe and Canada from patients with bicuspid AS treated with TAVR using the SAPIEN 3 valve. RESULTS: Seventy-nine patients underwent TAVR. Mean age was 76 ± 9 years; median STS risk score for mortality was 3.8% (interquartile range 2.3-5.5%). Median follow-up was 390 days (interquartile range 138-739 days). Device success was achieved in 95% of patients. Postimplantation mean aortic gradient decreased from 50.2 ± 16.2 to 8.8 ± 4.4 mmHg and no patient had more than mild aortic regurgitation. At last follow-up, there was persistent good valve performance. At 30 days and 1 year, the rates of all-cause mortality were 3.8 and 7.7%, stroke 1.2 and 1.2%, and the rate of new pacemakers 18 and 18%. CONCLUSIONS: Our data confirm that treating patients with stenotic bicuspid aortic valves is safe, effective, and has favorable valve performance over time.

Mitral regurgitation in patients undergoing transcatheter aortic valve implantation for degenerated surgical aortic bioprosthesis: Insights from PARTNER 2 Valve-in-Valve Registry.

BACKGROUND: Valve-in-valve (VIV) treatment with transcatheter aortic valve replacement (TAVR) is a viable option for patients with failing aortic bioprosthetic valves. Optimal management of those with concomitant mitral regurgitation (MR) remains undetermined. Therefore, we sought to assess the implications of concomitant MR in patients undergoing VIV-TAVR. METHODS AND RESULTS: The PARTNER 2 VIV registry enrolled patients with degenerated surgical aortic bioprosthesis at high risk for reoperation. Patients with core-laboratory echocardiographic assessment of MR were analyzed; severe MR was excluded. We compared patients with ≤mild MR versus moderate MR and assessed changes in MR severity and clinical outcomes. A total of 339 patients (89 initial registry, 250 continued access) underwent VIV procedures; mean age 79.0 ± 10.2 years, mean Society of Thoracic Surgeon score 8.9 ± 4.5%. At baseline, 228/339 (67.3%) had ≤mild MR and 111/339 (32.7%) had moderate MR. In paired analysis, there was significant improvement in ≥moderate MR from baseline to 30 days (32.6% vs. 14.5%, p < .0001 [n = 304]), and no significant change between 30 days and 1 year (13.4% vs. 12.1%, p = .56 [n = 224]) or 1 year and 2 years (11.0% vs. 10.4%, p = .81 [n = 182]). There was no difference in death or stroke between ≤mild MR and moderate MR at 30 days (4.0% vs. 7.2%, p = .20), 1 year (15.5% vs. 15.3%, p = .98) or 2 years (26.5% vs. 23.5%, p = .67). CONCLUSION: Moderate concomitant MR tends to improve with VIV-TAVR, and was not a predictor of long-term adverse outcomes in this cohort. In selected patients undergoing VIV-TAVR, it may be appropriate to conservatively manage concomitant MR. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT# 03225001.

Outcomes of transcatheter mitral valve replacement for degenerated bioprostheses, failed annuloplasty rings, and mitral annular calcification.

Aims: We sought to evaluate the outcomes of transcatheter mitral valve replacement (TMVR) for patients with degenerated bioprostheses [valve-in-valve (ViV)], failed annuloplasty rings [valve-in-ring (ViR)], and severe mitral annular calcification [valve-in-mitral annular calcification (ViMAC)]. Methods and results: From the TMVR multicentre registry, procedural and clinical outcomes of ViV, ViR, and ViMAC were compared according to Mitral Valve Academic Research Consortium (MVARC) criteria. A total of 521 patients with mean Society of Thoracic Surgeons score of 9.0 ± 7.0% underwent TMVR (322 patients with ViV, 141 with ViR, and 58 with ViMAC). Trans-septal access and the Sapien valves were used in 39.5% and 90.0%, respectively. Overall technical success was excellent at 87.1%. However, left ventricular outflow tract obstruction occurred more frequently after ViMAC compared with ViR and ViV (39.7% vs. 5.0% vs. 2.2%; P < 0.001), whereas second valve implantation was more frequent in ViR compared with ViMAC and ViV (12.1% vs. 5.2% vs. 2.5%; P < 0.001). Accordingly, technical success rate was higher after ViV compared with ViR and ViMAC (94.4% vs. 80.9% vs. 62.1%; P < 0.001). Compared with ViMAC and ViV groups, ViR group had more frequent post-procedural mitral regurgitation ≥moderate (18.4% vs. 13.8% vs. 5.6%; P < 0.001) and subsequent paravalvular leak closure (7.8% vs. 0.0% vs. 2.2%; P = 0.006). All-cause mortality was higher after ViMAC compared with ViR and ViV at 30 days (34.5% vs. 9.9% vs. 6.2%; log-rank P < 0.001) and 1 year (62.8% vs. 30.6% vs. 14.0%; log-rank P < 0.001). On multivariable analysis, patients with failed annuloplasty rings and severe MAC were at increased risk of mortality after TMVR [ViR vs. ViV, hazard ratio (HR) 1.99, 95% confidence interval (CI) 1.27-3.12; P = 0.003; ViMAC vs. ViV, HR 5.29, 95% CI 3.29-8.51; P < 0.001]. Conclusion: The TMVR provided excellent outcomes for patients with degenerated bioprostheses despite high surgical risk. However, ViR and ViMAC were associated with higher rates of adverse events and mid-term mortality compared with ViV.

Factors Promoting Survival After Prolonged Resuscitation Attempts: A Case of Survival With Good Neurological Outcome Following 60 Minutes of Downtime After Out-of-Hospital Cardiac Arrest.

BACKGROUND: Sudden cardiac arrest is a significant cause of death affecting approximately 25,000 people in Australia annually. METHODS: We present an out-of-hospital cardiac arrest (OHCA) with prolonged down time and recurrent ventricular arrhythmias treated with extra-corporeal membrane oxygenation. RESULTS: The patient survived to hospital discharge with good neurological outcome. CONCLUSION: The patient's excellent outcome was a result of immediate good quality CPR, high level premorbid function, reversible cause of arrest and rapid access to an ECMO centre.

Outcomes Following Melody Transcatheter Pulmonary Valve Implantation for Right Ventricular Outflow Tract Dysfunction in Repaired Congenital Heart Disease: First Reported Australian Single Centre Experience.

BACKGROUND: Transcatheter pulmonary valve implantation (TPVI) with the Melody® transcatheter pulmonary valve (TPV) has demonstrated good haemodynamic and clinical outcomes in the treatment of right ventricular outflow tract (RVOT) conduit dysfunction in patients with repaired congenital heart disease CHD. We present the first Australian single centre experience of patients treated with Melody TPV. METHOD: A prospective, observational registry was developed to monitor clinical and haemodynamic outcomes in patients with RVOT dysfunction treated with the Melody TPV (Medtronic Inc, Minneapolis, United States). RESULTS: Seventeen patients underwent TPVI with Melody TPV at The Prince Charles Hospital between January 2009 and February 2016 with a median (range) age of 34 (R: 15-60). Fifteen (88%) were NYHA Class 2 dyspnoea and 11 (59%) had corrected Tetralogy of Fallot. Indication for TPVI was stenosis in eight (47%), regurgitation in two (12%) and mixed dysfunction in seven (41%). Device implantation was successful in all patients. Peak RVOT gradient was significantly reduced and there was no significant regurgitation post procedure. There was one (6%) major procedural adverse event and two (12%) major adverse events at last recorded follow-up. There were no patient deaths. Follow-up cardiac magnetic resonance imaging revealed a significant reduction in indexed right ventricular end diastolic volume. CONCLUSION: This study confirms the safety and effectiveness of TPVI with Melody TPV for RVOT dysfunction in repaired CHD.

Factors Contributing to Acute Kidney Injury and the Impact on Mortality in Patients Undergoing Transcatheter Aortic Valve Replacement.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) patients are at a high risk of acute kidney injury (AKI). This study aimed to investigate AKI and the relationship with iodinated contrast media (ICM), whether there are significant pre- or peri- procedural variables predicting AKI, and whether AKI impacts on hospital length of stay and mortality. METHODS: Serum creatinine (SC) levels pre- and post- (peak) TAVR were recorded in 209 consecutive TAVR patients. AKI was defined by the Valve Academic Research Consortium 2 (VARC2) criteria. Baseline characteristics, procedural variables, hospital length of stay (LOS) and mortality at 72hours, 30 days and one year were analysed. RESULTS: Eighty-two of 209 (39%) patients suffered AKI. Mean ICM volume was 228cc, with no difference between patients with AKI and those with no AKI (227cc (213-240(95%CI)) vs 231cc (212-250) p=0.700)). Univariate and multivariate analysis demonstrated that chronic kidney disease, respiratory failure, previous stroke, the need for blood transfusion and valve repositioning were all predictors of AKI. Acute kidney injury increased LOS (5.6 days (3.8 - 7.5) vs 3.2 days (2.6 - 3.9) no AKI (P=0.004)) but was not linked to increased mortality. Mortality rates did increase with AKI severity. CONCLUSION: Acute kidney injury is a common complication of TAVR. The severity of AKI is important in determining mortality. Acute kidney injury appears to be independent of ICM use but pre-existing renal impairment and respiratory failure were predictors for AKI. Transcatheter aortic valve replacement device repositioning or retrieval was identified as a new risk factor impacting on AKI.

Pericardiocentesis ­ How to do it.

Pericardiocentesis is an important diagnostic and therapeutic technique, with the potential for significant morbidity and mortality if performed incorrectly. This article attempts to cover the anatomy, preparation, and techniques necessary to successfully perform pericardiocentesis.

A case of mobile aortic arch thrombus with systemic embolisation--a management dilemma.

We report the case of splenic infarct secondary to embolisation from a polypoid 17 mm×10 mm thoracic aorta thrombi in a 60 year-old female. The management and prognostic value of thoracic aorta thrombi are poorly defined in literature. This patient was successfully treated with oral anticoagulation as opposed to surgical intervention. Repeat transoesophageal echocardiography and computed tomography have demonstrated marked reduction in thrombi size with no further embolic event.

A repeat alcohol septal ablation procedure for hypertrophic obstructive cardiomyopathy where the first septal branch arose from the intermediate (ramus) artery.

Septal reduction therapy (via alcohol septal ablation or surgical myomectomy) is indicated in patients with hypertrophic obstructive cardiomyopathy (HOCM) who have NYHA class III/IV symptoms despite maximal medical therapy. In 90% of patients with HOCM the target septal artery arises from the LAD or diagonal artery. In the remaining 10% of cases it may arise from the ramus, proximal circumflex, or posterolateral or posterior descending branches of the RCA. We present a case where alcohol septal ablation was initially performed on the first septal branch arising from the left anterior descending artery. Left ventricular outflow tract (LVOT) obstruction with symptoms recurred. Upon repeat angiography, a large septal branch in fact arose from the proximal intermediate (ramus) artery. Alcohol ablation of this branch achieved a sustained response. This case highlights that correctly identifying the most suitable septal perforating artery, in addition to myocardial contrast echocardiography, may improve response rates and overall outcomes for patients with hypertrophic obstructive cardiomyopathy.

First results from the ACURATE Prime XL human feasibility study.

BACKGROUND/PURPOSE: This prospective, open-label, single-arm study evaluated transcatheter aortic valve replacement (TAVR) in patients with severe aortic stenosis with ACURATE Prime XL, an iteration of the ACURATE neo2 device designed with improved radial force and adaptations for compatibility with a larger annulus diameter (≥ 26.5 mm and ≤ 29 mm based on pre-procedure diagnostic imaging). METHODS: The composite primary device success endpoint was based on Valve Academic Research Consortium (VARC)-2 criteria. The primary safety endpoint was a composite of all-cause mortality and all stroke at 30 days. Aortic valve (AV) performance, including mean AV gradient, AV area, and grade of paravalvular leak (PVL), was assessed by an independent core laboratory. RESULTS: 13 male patients were enrolled at 3 Australian centers (mean age: 83.1 years; 10 of 13 were considered high/extreme operative risk). 61.5 % of patients met the primary device success endpoint. At 30 days, no patients experienced death or stroke; one patient received a permanent pacemaker. Mean AV gradient improved from baseline (42.7 ± 11.0 mmHg) to discharge (7.7 ± 2.5 mmHg) and through 30 days (7.2 ± 2.3 mmHg). Mean AV area was 0.8 ± 0.1 cm2 at baseline, 1.9 ± 0.3 cm2 at discharge, and 1.7 ± 0.3 cm2 at 30 days. Per core-laboratory adjudication, no patient had moderate or severe PVL at 30 days; 91.7 % had no/trace PVL and 8.3 % had mild PVL. CONCLUSIONS AND RELEVANCE: In this first-in-human feasibility study of the ACURATE Prime XL valve, there were no safety concerns, and no deaths or strokes within 30 days. Valve hemodynamics were favorable, and no patient had >mild PVL.

Prehospital Activation of the Cardiac Catheterization Laboratory in ST-Segment-Elevation Myocardial Infarction for Primary Percutaneous Coronary Intervention.

Background Prehospital activation of the cardiac catheter laboratory is associated with significant improvements in ST-segment-elevation myocardial infarction (STEMI) performance measures. However, there are equivocal data, particularly within Australia, regarding its influence on mortality. We assessed the association of prehospital activation on performance measures and mortality in patients with STEMI treated with primary percutaneous coronary intervention from the Queensland Cardiac Outcomes Registry (QCOR). Methods and Results Consecutive ambulance-transported patients with STEMI treated with primary percutaneous coronary intervention were analyzed from January 1, 2017 to December 31, 2020 from the QCOR. The total and direct effects of prehospital activation on the primary outcomes (30-day and 1-year cardiovascular mortality) were estimated using logistic regression analyses. Secondary outcomes were STEMI performance measures. Among 2498 patients (mean age: 62.2±12.4 years; 79.2% male), 73% underwent prehospital activation. Median door-to-balloon time (34 minutes [26-46] versus 86 minutes [68-113]; P<0.001), first-electrocardiograph-to-balloon time (83.5 minutes [72-98] versus 109 minutes [81-139]; P<0.001), and proportion of patients meeting STEMI targets (door-to-balloon <60 minutes 90% versus 16%; P<0.001), electrocardiograph-to-balloon time <90 minutes (62% versus 33%; P<0.001) were significantly improved with prehospital activation. Prehospital activation was associated with significantly lower 30-day (1.6% versus 6.6%; P<0.001) and 1-year cardiovascular mortality (2.9% versus 9.5%; P<0.001). After adjustment, no prehospital activation was strongly associated with increased 30-day (odds ratio [OR], 3.6 [95% CI, 2.2-6.0], P<0.001) and 1-year cardiovascular mortality (OR, 3.0 [95% CI, 2.0-4.6]; P<0.001). Conclusions Prehospital activation of cardiac catheterization laboratory for primary percutaneous coronary intervention was associated with significantly shorter time to reperfusion, achievement of STEMI performance measures, and lower 30-day and 1-year cardiovascular mortality.