Does Gender Affect the Outcomes of Myocardial Revascularization for Left-Main Coronary Artery Disease?

Currently, gender is not considered in the choice of the revascularization strategy for patients with unprotected left main coronary artery (ULMCA) disease. This study analyzed the effect of gender on the outcomes of percutaneous coronary intervention (PCI) vs coronary artery bypass grafting (CABG) in patients with ULMCA disease. Females who had PCI (n = 328) were compared with females who had CABG (n = 132) and PCI in males (n = 894) was compared with CABG (n = 784). Females with CABG had higher overall hospital mortality and major adverse cardiovascular events (MACE) than females with PCI. Male patients with CABG had higher MACE; however, mortality did not differ between males with CABG vs PCI. In female patients, follow-up mortality was significantly higher in CABG patients, and target lesion revascularization was higher in patients with PCI. Male patients had no difference in mortality and MACE between groups; however, MI was higher with CABG, and congestive heart failure was higher with PCI. In conclusion, women with ULMCA disease treated with PCI could have better survival with lower MACE compared with CABG. These differences were not evident in males treated with either CABG or PCI. PCI could be the preferred revascularization strategy in women with ULMCA disease.

Single Versus Dual Antiplatelet Therapy After Coronary Artery Bypass Grafting for Unprotected Left-Main Coronary Disease.

BACKGROUND: The use of dual antiplatelet therapy (DAPT) after coronary revascularization for left-main disease is still debated. The study aimed to characterize patients who received dual versus single antiplatelet therapy (SAPT) after coronary artery bypass grafting (CABG) for unprotected left-main disease and compare the outcomes of those patients. RESULTS: This multicenter retrospective cohort study included 551 patients who were grouped into 2 groups: patients who received SAPT (n = 150) and those who received DAPT (n = 401). There were no differences in age ( P = 0.451), gender ( P = 0.063), smoking ( P = 0.941), diabetes mellitus ( P = 0.773), history of myocardial infarction ( P = 0.709), chronic kidney disease ( P = 0.615), atrial fibrillation ( P = 0.306), or cerebrovascular accident ( P = 0.550) between patients who received SAPT versus DAPT. DAPTs were more commonly used in patients with acute coronary syndrome [87 (58%) vs. 273 (68.08%); P = 0.027], after off-pump CABG [12 (8%) vs. 73 (18.2%); P = 0.003] and in patients with radial artery grafts [1 (0.67%) vs. 32 (7.98%); P < 0.001]. While SAPTs were more commonly used in patients with low ejection fraction [55 (36.67%) vs. 61 (15.21%); P < 0.001] and in patients with postoperative acute kidney injury [27 (18%) vs. 37 (9.23%); P = 0.004]. The attributed treatment effect of DAPT for follow-up major adverse cerebrovascular and cardiac events was not significantly different from that of SAPT [ß, -2.08 (95% confidence interval (CI), -20.8-16.7); P = 0.828]. The attributed treatment effect of DAPT on follow-up all-cause mortality was not significantly different from that of SAPT [ß, 4.12 (CI, -11.1-19.32); P = 0.595]. There was no difference in bleeding between groups ( P = 0.666). CONCLUSIONS: DAPTs were more commonly used in patients with acute coronary syndrome, after off-pump CABG, and with radial artery grafts. SAPTs were more commonly used in patients with low ejection fraction and acute kidney injury. Patients on DAPT after CABG for left-main disease had comparable major adverse cerebrovascular and cardiac events and survival to patients on SAPT, with no difference in bleeding events.

Percutaneous coronary intervention vs. coronary artery bypass grafting in emergency and non-emergency unprotected left-main revascularization.

BACKGROUND: The optimal revascularization strategy in patients with left main coronary artery (LMCA) disease in the emergency setting is still controversial. Thus, we aimed to compare the outcomes of percutaneous coronary interventions (PCI) vs. coronary artery bypass grafting (CABG) in patients with and without emergent LMCA disease. METHODS: This retrospective cohort study included 2138 patients recruited from 14 centers between 2015 and 2019. We compared patients with emergent LMCA revascularization who underwent PCI (n = 264) to patients who underwent CABG (n = 196) and patients with non-emergent LMCA revascularization with PCI (n = 958) to those who underwent CABG (n = 720). The study outcomes were in-hospital and follow-up all-cause mortality and major adverse cardiovascular and cerebrovascular events (MACCE). RESULTS: Emergency PCI patients were older and had a significantly higher prevalence of chronic kidney disease, lower ejection fraction, and higher EuroSCORE than CABG patients. CABG patients had significantly higher SYNTAX scores, multivessel disease, and ostial lesions. In patients presenting with arrest, PCI had significantly lower MACCE (P = 0.017) and in-hospital mortality (P = 0.016) than CABG. In non-emergent revascularization, PCI was associated with lower MACCE in patients with low (P = 0.015) and intermediate (P < 0.001) EuroSCORE. PCI was associated with lower MACCE in patients with low (P = 0.002) and intermediate (P = 0.008) SYNTAX scores. In non-emergent revascularization, PCI was associated with reduced hospital mortality in patients with intermediate (P = 0.001) and high (P = 0.002) EuroSCORE compared to CABG. PCI was associated with lower hospital mortality in patients with low (P = 0.031) and intermediate (P = 0.001) SYNTAX scores. At a median follow-up time of 20 months (IQR: 10-37), emergency PCI had lower MACCE compared to CABG [HR: 0.30 (95% CI 0.14-0.66), P < 0.003], with no significant difference in all-cause mortality between emergency PCI and CABG [HR: 1.18 (95% CI 0.23-6.08), P = 0.845]. CONCLUSIONS: PCI could be advantageous over CABG in revascularizing LMCA disease in emergencies. PCI could be preferred for revascularization of non-emergent LMCA in patients with intermediate EuroSCORE and low and intermediate SYNTAX scores.

Left Main Coronary Artery Revascularization in Patients with Impaired Renal Function: Percutaneous Coronary Intervention versus Coronary Artery Bypass Grafting.

INTRODUCTION: The evidence about the optimal revascularization strategy in patients with left main coronary artery (LMCA) disease and impaired renal function is limited. Thus, we aimed to compare the outcomes of LMCA disease revascularization (percutaneous coronary intervention [PCI] vs. coronary artery bypass grafting [CABG]) in patients with and without impaired renal function. METHODS: This retrospective cohort study included 2,138 patients recruited from 14 centers between 2015 and 2,019. We compared patients with impaired renal function who had PCI (n= 316) to those who had CABG (n = 121) and compared patients with normal renal function who had PCI (n = 906) to those who had CABG (n = 795). The study outcomes were in-hospital and follow-up major adverse cardiovascular and cerebrovascular events (MACCE). RESULTS: Multivariable logistic regression analysis showed that the risk of in-hospital MACCE was significantly higher in CABG compared to PCI in patients with impaired renal function (odds ratio [OR]: 8.13 [95% CI: 4.19-15.76], p < 0.001) and normal renal function (OR: 2.59 [95% CI: 1.79-3.73]; p < 0.001). There were no differences in follow-up MACCE between CABG and PCI in patients with impaired renal function (HR: 1.14 [95% CI: 0.71-1.81], p = 0.585) and normal renal function (HR: 1.12 [0.90-1.39], p = 0.312). CONCLUSIONS: PCI could have an advantage over CABG in revascularization of LMCA disease in patients with impaired renal function regarding in-hospital MACCE. The follow-up MACCE was comparable between PCI and CABG in patients with impaired and normal renal function.

Management and clinical outcomes of cardiogenic shock in King Abdulaziz University Hospital: A retrospective study.

OBJECTIVES: To assess frequencies of various management approaches in cardiogenic shock (CS) and their clinical outcomes. Cardiogenic shock is a state of organ hypoperfusion and hypoxia caused by cardiac failure. METHODS: In this retrospective record review, we assessed the presentations, vital signs, laboratory readings, and treatments for 188 consecutive CS inpatients from 2010-2021. Patients were labeled as "ischemic CS" or "non-ischemic CS" based on the occurrence of myocardial infarction as the precipitating cause, and "post-operative CS" if they had undergone cardiac surgery. In-hospital mortality was the primary endpoint of the study. RESULTS: We identified 118 (62.8%) ischemic, 64 (34%) non-ischemic, and 6 (3.2%) postoperative CS patients. The study population had a high mortality rate (85.1%). Logistic regression analysis revealed that dopamine (p=0.040) and epinephrine (p=0.001) were independent predictors of mortality, while dobutamine (p=0.004) and digoxin (p=0.044) associated with increased survival. No significant association with mortality was found between either PCI or IABP. No significant difference in mortality was observed between CS subgroups. CONCLUSION: Variations in outcomes occurred with different medications. Mortality was higher in patients receiving dopamine or epinephrine and lower in those receiving dobutamine or digoxin. Implementation of clinical trials for investigation of the mortality benefit observed with dobutamine can serve towards formulation of new guidelines for improvement of CS mortality rates.

Outcomes of Left Main Revascularization in Patients with Anemia: Gulf Left Main Registry.

INTRODUCTION: The aim of this study was to evaluate the effects of baseline anemia and anemia following revascularization on outcomes in patients with unprotected left main coronary artery (ULMCA) disease. METHODS: This was a retrospective, multicenter, observational study conducted between January 2015 and December 2019. The data on patients with ULMCA who underwent revascularization through percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) were stratified by the hemoglobin level at baseline into anemic and non-anemic groups to compare in-hospital events. The pre-discharge hemoglobin following revascularization was categorized into very low (<80 g/L for men and women), low (≥80 and ≤119 g/L for women and ≤129 g/L for men), and normal (≥130 g/L for men and ≥120 g/L for women) to assess impact on follow-up outcomes. RESULTS: A total of 2,138 patients were included, 796 (37.2%) of whom had anemia at baseline. A total of 319 developed anemia after revascularization and moved from being non-anemic at baseline to anemic at discharge. There was no difference in hospital major adverse cardiac and cerebrovascular event (MACCE) and mortality between CABG and PCI in anemic patients. At a median follow-up time of 20 months (interquartile range [IQR]: 27), patients with pre-discharge anemia who underwent PCI had a higher incidence of congestive heart failure (CHF) (p < 0.0001), and those who underwent CABG had significantly higher follow-up mortality (HR: 9.85 (95% CI: 2.53-38.43), p = 0.001). CONCLUSION: In this Gulf LM study, baseline anemia had no impact upon in-hospital MACCE and total mortality following revascularization (PCI or CABG). However, pre-discharge anemia is associated with worse outcomes after ULMCA disease revascularization, with significantly higher all-cause mortality in patients who had CABG, and a higher incidence of CHF in PCI patients, at a median follow-up time of 20 months (IQR: 27).

One Versus Two Stents Strategies for Unprotected Left Main Intervention: Gulf Left Main Registry.

The optimal stenting strategy for unprotected left main coronary artery (ULMCA) disease remains debated. This retrospective observational study (Gulf Left Main Registry) analyzed the outcomes of 1 vs 2 stents in patients with unprotected left main percutaneous coronary intervention (PCI). Overall, 1222 patients were evaluated; 173 had 1 stent and 1049 had 2 stents. The 2-stent group was older with more comorbidities, higher mean SYNTAX scores, and more distal bifurcation lesions. In the 1-stent group, in-hospital events were significant for major bleeding, and better mean creatinine clearance. At median follow-up of 20 months, the 1-stent group was more likely to have target lesion revascularization (TLR). Total mortality was numerically lower in the 1-stent group (.00% vs 2.10%); however, this was not statistically significant (P=.068). Our analysis demonstrates the benefits of a 2-stent approach for ULMCA patients with high SYNTAX scores and lesions in both major side branches, while the potential benefit of a 1-stent approach for less complex ULMCA was also observed. Further studies with longer follow-up are needed to definitively demonstrate the optimal approach.

Impact of left ventricular ejection fraction on outcomes after left main revascularization: g-LM Registry.

AIMS: The impact of left ventricular dysfunction on clinical outcomes following revascularization is not well established in patients with unprotected left main coronary artery disease (ULMCA). In this study, we evaluated the impact of left ventricular ejection fraction (LVEF) on clinical outcomes of patients with ULMCA requiring revascularization with percutaneous coronary intervention (PCI) compared with coronary artery bypass graft (CABG). METHODS: The details of the design, methods, end points, and relevant definitions are outlined in the Gulf Left Main Registry: a retrospective, observational study conducted between January 2015 and December 2019 across 14 centres in 3 Gulf countries. In this study, the data on patients with ULMCA who underwent revascularization through PCI or CABG were stratified by LVEF into three main subgroups; low (l-LVEF <40%), mid-range (m-LVEF 40-49%), and preserved (p-LVEF ≥50%). Primary outcomes were hospital major adverse cardiovascular and cerebrovascular events (MACCE) and mortality and follow-up MACCE and mortality. RESULTS: A total of 2137 patients were included; 1221 underwent PCI and 916 had CABG. During hospitalization, MACCE was significantly higher in patients with l-LVEF [(10.10%), P = 0.005] and m-LVEF [(10.80%), P = 0.009], whereas total mortality was higher in patients with m-LVEF [(7.40%), P = 0.009] and p-LVEF [(7.10%), P = 0.045] who underwent CABG. There was no mortality difference between groups in patients with l-LVEF. At a median follow-up of 15 months, there was no difference in MACCE and total mortality between patients who underwent CABG or PCI with p-LVEF and m-LVEF. CONCLUSION: CABG was associated with higher in-hospital events. Hospital mortality in patients with l-LVEF was comparable between CABG and PCI. At 15 months' follow-up, PCI could have an advantage in decreasing MACCE in patients with l-LVEF.

Outcomes of Myocardial Revascularization in Diabetic Patients With Left Main Coronary Artery Disease: A Multicenter Observational Study From Three Gulf Countries.

BACKGROUND: Real-world data for managing patients with diabetes and left main coronary artery (LMCA) disease are scarce. We compared percutaneous coronary intervention (PCI) outcomes versus coronary artery bypass grafting (CABG) in diabetes and LMCA disease patients. METHODS: We retrospectively studied patients with LMCA presented to 14 centers from 2015 to 2019. The study included 2138 patients with unprotected LMCA disease; 1468 (68.7 %) had diabetes. Patients were grouped into; diabetes with PCI (n = 804) or CABG (n = 664) and non-diabetes with PCI (n = 418) or CABG (n = 252). RESULTS: In diabetes, cardiac (34 (5.1 %) vs. 22 (2.7 %); P = 0.016), non-cardiac (13 (2 %) vs. 6 (0.7 %); P = 0.027) and total hospital mortality (47 (7.1 %) vs. 28 (3.5 %); P = 0.0019), myocardial infarction (45 (6.8 %) vs. 11 (1.4 %); P = 0.001), cerebrovascular events (25 (3.8 %) vs. 12 (1.5 %); P = 0.005) and minor bleeding (65 (9.8 %) vs. 50 (6.2 %); P = 0.006) were significantly higher in CABG patients compared to PCI; respectively. The median follow-up time was 20 (10-37) months. In diabetes, total mortality was higher in CABG (P = 0.001) while congestive heart failure was higher in PCI (P = 0.001). There were no differences in major adverse cerebrovascular events and target lesion revascularization between PCI and CABG. Predictors of mortality in diabetes were high anatomical SYNTAX, peripheral arterial disease, chronic kidney disease, and cardiogenic shock. CONCLUSIONS: In this multicenter retrospective study, we found no significant difference in clinical outcomes during the short-term follow-up between PCI with second-generation DES and CABG except for lower total mortality and a higher rate of congestive heart failure in PCI group of patients. Randomized trials to characterize patients who could benefit from each treatment option are needed.

Unprotected Left Main Revascularization in the Setting of Non-coronary Atherosclerosis: Gulf Left Main Registry.

Coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) in revascularization of left main coronary artery (LMCA) disease has been evaluated in previous studies. However, there has been minimal study of the relationship between co-existing non-coronary atherosclerosis (NCA) and LMCA disease revascularization. We aim to examine this relationship. The Gulf-LM study is a retrospective analysis of unprotected LMCA revascularization cases undergoing PCI with second generation drug-eluting stent vs CABG across 14 centers within 3 Gulf countries between January 2015 and December 2019. A total of 2138 patients were included, 381 with coexisting NCA and 1757 without. Outcomes examined included major adverse cardiovascular and cerebrovascular events (MACCE), cardiac and non-cardiac death, and all bleeding. In patients with NCA, preexisting myocardial infarction and congestive heart failure were more common, with PCI being the most common revascularization strategy. A statistically significant reduction in in-hospital MACCE and all bleeding was noted in patients with NCA undergoing PCI as compared to CABG. At a median follow-up of 15 months, MACCE and major bleeding outcomes continued to favor the PCI group, though no such difference was identified between revascularization strategies in patients without NCA.In this multicenter retrospective study of patients with and without NCA who require revascularization (PCI and CABG) for unprotected LMCA disease, PCI demonstrated a better clinical outcome in MACCE both in-hospital and during the short-term follow-up in patients with NCA. However, no such difference was observed in patients without NCA.

Percutaneous Coronary Intervention Vs Coronary Artery Bypass Surgery for Unprotected Left Main Coronary Disease: G-LM Registry.

Coronary artery bypass surgery (CABG) has been the standard of care for revascularization for patients with obstructive unprotected left main coronary disease (ULMCA). There have been multiple randomized and registry data demonstrating the technical and clinical efficacy of PCI in certain patients with ULMCA. The purpose of this study is to evaluate clinical outcomes of ULMCA PCI as compared to CABG in patients requiring revascularization in three Gulf countries. All ULMCA cases treated by PCI with DES versus CABG were retrospectively identified from 14 centers in 3 Arab Gulf countries (KSA, UAE, and Bahrain) from January 2015 to December 2019. In total, 2138 patients were included: 1222 were treated with PCI versus 916 with CABG. Patients undergoing PCI were older, and had higher comorbidities and mean European System for Cardiac Operative Risk Evaluation (EuroSCORE). Aborted cardiac arrest and cardiogenic shock were reported more in the PCI group at hospital presentation. In addition, lower ejection fractions were reported in the PCI group. In hospital mortality and major adverse cardiovascular and cerebrovascular events (MACCE) occurred more in patients undergoing CABG than PCI. At median follow-up of 15 months (interquartile range, 30), no difference was observed in freedom from revascularization, MACCE, or total mortality between those treated with PCI and CABG. While findings are similar to Western data registries, continued follow-up will be needed to ascertain whether this pattern continues into latter years.

Merits of Different Ventricular Lead Locations on Left Ventricular Myocardial Strain and Dyssynchrony in Patients with Cardiac Resynchronization Therapy.

BACKGROUND: The idea behind cardiac resynchronization therapy (CRT) is to pace both ventricles resulting in a synchronized electro-mechanical coupling of the left ventricle (LV), meaning every effort should be made to improve the percentage of CRT responders. OBJECTIVES: This study aimed at demonstrating the short-term effect of right ventricular apical (RVA) and mid-septal (RVS) lead locations combined with different LV lead positions on LV myocardial strain, dyssynchrony, and clinical outcomes. METHODS: We examined 60 patients with indication for CRT before and after 6 months of implantation for clinical outcome and CRT response (6-min walk test [6MWT], NYHA class, decrease in left ventricular end systolic volume [LVESV] by >15%), dyssynchrony, and myocardial strain. RESULTS: After 6 months of follow-up, the two RV lead locations represented a significant improvement in 6MWT, left ventricular ejection fraction, and LVESV in comparison to baseline values, but no significant difference was found between both groups. With regards to NYHA class improvement, p values were insignificant between the groups (0.44 and 0.88) at baseline and 6 months after implantation, respectively. The mean 6MWT was 273.8 m in the RVA group compared to 279.0 m in the RVS group (p = 0.84) at baseline. After 6 months of CRT implantation, the 6MWT mean was 326.5 m in the RVA group compared to 316.2 m in the RVS group (p = 0.74). The posterolateral cardiac vein site showed a significant improvement when combined with RVS location in interventricular and intraventricular dyssynchrony, global longitudinal strain, global circumferential strain, and apical circumferential strain (p = 0.01 0.032, 0.02, 0.005, and 0.049), respectively. CONCLUSION: RVS is not inferior and provides a good alternative to RVA pacing in short-term follow-up. However, the QRS duration, myocardial strain, and dyssynchrony varies depending on RV and LV stimulation sites. Long-term morbidity and mortality outcomes according to LV lead location in coronary sinus need more assessment.

Clinical outcome of intracoronary versus intravenous high-dose bolus administration of tirofiban in diabetic patients undergoing primary percutaneous coronary intervention.

BACKGROUND: Previous trials remain inconsistent regarding the advantages and hazards related to intracoronary (IC) compared with intravenous (IV) administration of thrombolytics. We aimed to evaluate the safety and effectiveness of IC versus IV tirofiban administration in diabetic patients (DM) with acute ST-segment elevation myocardial infarction (STEMI) during primary percutaneous coronary intervention (PCI). METHODS: This trial included 95 patients who were randomised to high-dose bolus plus a maintenance dose of tirofiban administered either IV or IC. The groups were compared for the incidence of composite major adverse cardiac events (MACE) at 30 days. Levels of cardiac markers were recorded pre- and post-intervention for myocardial perfusion. RESULTS: The MACE were not different between the groups, but post-procedure myocardial blush grade (MBG) 3 and thrombolysis in myocardial infarction (TIMI) 3 flow were significant in the IC group (p = 0.45, 0.21, respectively), favouring the IC strategy. Peak values of both creatine kinase-muscle/brain (CK-MB) and high-sensitivity troponin T (hs-TnT) were significantly lower in the IC group (155.68 ± 121, 4291 ± 334 ng/dl) versus the IV group (192.4 ± 86, 5342 ± 286 ng/dl) (p = 0.021, p = 0.035, respectively). The peak value was significantly lower in the IC group than the IV group in terms of ST-segment resolution and 30-day left ventricular ejection fraction (LVEF) (p = 0.016 and 0.023, respectively). CONCLUSION: Thirty days post PCI, IC tirofiban was more efficient in ameliorating blood flow in the coronary arteries and myocardial tissue perfusion in DM patients after STEMI despite bleeding events, and MACE rates showed no significant difference between the groups. The IC group showed better improvement in LVEF.

Current Evidence on Platelet P2Y12 Receptor Inhibitors: Is There Still a Role for Clopidogrel in 2015?

Antiplatelets play a significant role in the management of patients with coronary disease. Novel inhibitors of the platelet P2Y12 receptor have more rapid, potent, and consistent inhibitory effect on platelets compared with clopidogrel. Evidence from large clinical studies have defined populations in which novel agents are superior to clopidogrel. Ticagrelor or prasugrel in addition to aspirin should be used preferentially for patients with ST-elevation myocardial infarction because of significant anti-ischemic benefits. In patients with non-ST segment elevation acute coronary syndromes, ticagrelor has proven superiority over clopidogrel whether or not an invasive strategy is adopted, and prasugrel has been shown to be beneficial when started at the time of percutaneous coronary intervention. Of note, neither prasugrel nor ticagrelor have been studied in patients who underwent percutaneous coronary intervention for stable coronary disease or those who required 'triple therapy.' In these situations, clopidogrel should remain the default until further data are available. Prolonged use of clopidogrel in patients with drug-eluting stents beyond 12 months is emerging as a novel indication for the agent.

Integrating anatomical and functional imaging for the assessment of coronary artery disease.

Coronary artery disease (CAD) is a leading cause of morbidity and mortality. Invasive cardiac angiography with fractional flow reserve measurement allows for the anatomical and functional assessment of CAD. Given the invasive nature of invasive cardiac angiography and the risks of procedure-related complications, research has focused upon noninvasive methods for anatomical and functional measures of CAD. As such, there is growing interest in the development of hybrid imaging because it may provide incremental diagnostic information over each imaging modality alone. We will provide an overview of the evidence to date on the anatomical and functional stratification of CAD and current hybrid techniques.

Incremental diagnostic benefit of resolution recovery software in patients with equivocal myocardial perfusion single-photon emission computed tomography (SPECT).

BACKGROUND: Though myocardial perfusion imaging (MPI) with single-photon emission computed tomography (SPECT) is an established diagnostic method, equivocal studies are commonly encountered. New software has been introduced that incorporates resolution recovery (RR) and noise regulation into the reconstruction algorithm and has been used to facilitate "half-dose" and "half-time" studies. Its utility with "full-time, full-dose" acquisition has not been well studied. OBJECTIVE: We sought to understand the potential benefit of incorporating RR software in equivocal SPECT studies. METHODS: Patients with full-time, full-dose SPECT MPI were reviewed and those with equivocal results, who subsequently underwent cardiac Rb-82 positron emission tomography (PET) scan were identified. Image reconstruction was performed with iterative reconstruction (IR), attenuation correction (IR + AC), and RR software (IR + AC + RR). Images were anonymized and read blindly by consensus of two experienced readers. All images were qualitatively assessed and semi-quantitatively graded using summed stress and summed rest scores. RESULTS: 45 patients were included (28 males, age = 59.6 ± 9.9 years) and the diagnostic accuracy of each of the reconstruction algorithms (IR, IR + AC, IR + AC + RR) was compared to Rb-82 PET. Agreement of clinical diagnosis of each SPECT reconstruction with Rb-PET showed incremental improvement. The agreement with PET for IR + AC + RR (κ = 0.66, CI 0.454-0.875) is significantly better than for IR (κ = 0.22, CI 0.0-0.450, P = .005) and for IR + AC (κ = 0.32, CI 0.077-0.563, P = .03). Also, IR + AC + RR improved the clinical diagnosis in 14 cases and with overall improvement of reclassification proportion of 23.5% compared to IR (P = .01). Using PET as a reference standard, ROC curves were created for IR + AC + RR, IR + AC, and IR which showed incremental value of the area under the curve of IR + AC + RR (AUC: 0.87; CI 0.76-0.98) over IR + AC (AUC: 0.75; CI 0.61-0.89, P = .078), and over IR (AUC 0.68; CI 0.52-0.84, P = .025). CONCLUSION: The addition of RR may help in the diagnosis of patients with equivocal SPECT MPI without the need for additional testing. Further prospective studies are needed to define the role of this new software.