Efficacy and safety of percutaneous patent foramen ovale closure in patients with a hypercoagulable disorder.

BACKGROUND: Transcatheter closure of patent foramen ovale (PFO) in patients with cryptogenic stroke reduces the rate of recurrent events. Although presence of thrombophilia increases the risk for paradoxical emboli through a PFO, such patients were excluded from large randomized trials. OBJECTIVES: We compared the safety and efficacy of percutaneous PFO closure in patients with and without a hypercoagulable state. METHODS: Data from 800 consecutive patients undergoing percutaneous PFO closure in our medical center were analyzed. All patients were independently evaluated by specialists in neurology, cardiology, hematology, and vascular medicine. A post-procedural treatment of at least 3 months of anticoagulation was utilized in patients with thrombophilia. Follow-up events included death, recurrent neurological events, and the need for reintervention for significant residual shunt. RESULTS: A hypercoagulable state was found in 239 patients (29.9%). At median follow-up of 41.9 months, there were no differences in the frequencies of stroke or transient ischemic attack between patients with or without thrombophilia (2.5% in non-hypercoagulable group vs. 3.4% in hypercoagulable group, log-rank test p = 0.35). There were no significant differences in baseline demographics, echocardiographic characteristics, procedural success, or complications between groups. CONCLUSION: Percutaneous PFO closure is a safe and effective therapeutic approach for patients with cryptogenic stroke and an underlying hypercoagulable state.

Extracorporeal membrane oxygenation in acute massive pulmonary embolism: a case series and review of the literature.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) has been used to stabilize patients with massive pulmonary embolism though few reports describe this approach. We describe the presentation, management and outcomes of patients who received ECMO for massive pulmonary embolism (PE) in our pulmonary embolism response team (PERT) registry. METHODS: We enrolled a consecutive cohort of patients with confirmed PE for whom PERT was activated and selected patients treated with ECMO. We prospectively captured clinical, therapeutic and outcome data at the time of PERT activation and during the follow-up period for up to 365 days. RESULTS: Thirteen patients who had PERT activation with confirmed PE diagnosis have undergone ECMO since the initiation of our PERT program in 2012. The mean age was 49 ± 19 years. Six (46%) patients were female. All the patients had cardiac arrest, either as an initial presentation or in-hospital cardiac arrest after presentation. All the patients exhibited right ventricular (RV) dilation on echocardiogram with RV hypokinesis. Eight (62%) patients received systemic thrombolysis with intravenous tissue plasminogen activator (tPA) and three (23%) patients underwent catheter-directed thrombolysis therapy using the EKOS system (EKOS Corporation, Bothell, WA, USA). Four (31%) patients underwent surgical embolectomy. Mean ECMO duration was 5.5 days, ranging from 2-18 days. Thirty-day mortality was 31% and one-year mortality was 54%. CONCLUSIONS: Patients with massive pulmonary embolism who suffer a cardiac arrest have high morbidity and mortality. ECMO can be used in conjunction with systemic thrombolysis, catheter-directed therapy or as a bridge to surgical embolectomy.

Bivalirudin versus heparin in patients undergoing percutaneous transcatheter aortic valve interventions: A systematic review and meta-analysis.

BACKGROUND: Bivalirudin may be an effective anticoagulation alternative to heparin as anticoagulant agent in percutaneous transcatheter aortic valve interventions (PAVI). We aimed to compare safety and efficacy of bivalirudin versus heparin as the procedural anticoagulant agent in patients undergoing PAVI. METHODS: We conducted an electronic database search of all published data. The primary efficacy endpoints were all-cause mortality, cardiovascular mortality, myocardial infarction, and stroke. Safety endpoints include major and life-threatening bleed according to VARC and BARC bleeding, blood transfusion, vascular complications, and acute kidney injury. Odds ratios (OR) and 95% confidence intervals (CI) computed using the Mantel-Haenszel method. RESULTS: Three studies (n = 1690 patients) were included, one randomized trial and two observational studies. There was a significant difference favoring bivalirudin over heparin for myocardial infarction (OR 0.41, 95%CI 0.20-0.87). There was no significant difference in all-cause mortality at 30 days (OR 0.97, 95%CI 0.62-1.52), cardiovascular mortality (OR 1.03, 95%CI 0.52-2.05), stroke (OR 1.23, 95%CI 0.62-2.46), vascular complications (OR 0.96, 95%CI 0.70-1.32), acute kidney injury (OR 1.03, 95%CI 0.53-2.00), blood transfusion (OR 0.67, 95% CI 0.45-1.01), major and life-threatening bleed (OR 0.74, 95%CI 0.37-1.49), and BARC bleeding (OR 0.52, 95%CI 0.23-1.18). CONCLUSIONS: In patient undergoing aortic valve interventions, no difference was seen between the use of bivalirudin and heparin as the procedural anticoagulant agent, except for a significant lower myocardial infarction events when bivalirudin was used. Further large randomized trials are needed to confirm current results.

Advances in Percutaneous Therapies for Peripheral Artery Disease: Drug-Coated Balloons.

PURPOSE OF REVIEW: This review paper provides a summary on the use of drug-coated balloons in peripheral artery disease. It covers the main drug-coated balloon (DCB) trials. It is divided into categories of lesions: superficial femoral artery and popliteal lesions, infra-popliteal lesions and in-stent restenosis. It also includes an overview of the future of DCBs, highlighting the main ongoing trials. RECENT FINDINGS: The latest research on DCB focuses on newer types of DCBs, mainly paclitaxel-coated but with lower doses. Another area of latest DCB research is its use in superficial femoral artery and popliteal artery in-stent restenosis, with superior outcomes. Drug-coated balloons produce better outcomes than percutaneous transluminal angioplasty alone in de novo and in-stent restenosis lesions of superficial femoral artery and popliteal arteries. More data are needed to demonstrate efficacy and safety of DCBs in infrapopliteal disease. Newer DCBs and adjunctive therapy may provide improved outcomes for peripheral artery disease interventions.

Tricuspid regurgitation and implantable devices.

BACKGROUND: There are limited and conflicting data regarding the prevalence of tricuspid regurgitation (TR) after cardiac device implantation (implantable cardioverter defibrillator [ICD]; permanent pacemaker [PPM]). OBJECTIVE: The goal of this study was to assess the prevalence of TR after cardiac device implantation and determine its clinical significance. METHODS: A total of 1,596 patients, who had cardiac devices implanted between 2005 and 2011 at the Cleveland Clinic and had at least one preimplantation echocardiogram and at least one postimplantation echocardiogram were included in this study. A total of 3,566 postimplantation echocardiograms were available for the 1,596 patients (median follow-up 10 months). The primary end point was postimplantation TR and the secondary end point was all-cause mortality after implantation. We have used a cumulative logistic nonlinear mixed-effects model to assess the temporal trend of TR prevalence and a parametric multiphase hazard model to assess survival. RESULTS: Of the 1,596 patients (mean age: 60 ± 10 years, 61% of patients were men), 985 (62%) had ICDs (including 334 patients with cardiac resynchronization therapy defibrillator) and 611 (38%) had PPMs. The prevalence of grade 3 or 4+ TR increased from 27% to 31% by 1 month and to 35% at 4 years. Accordingly, prevalence of grade 0/1+ TR decreased from 46% preimplantation to 37% at 1 month and to 32% at 4 years. Device type (ICD vs PPM) and the number of leads placed did not have an effect on postimplantation TR (P > 0.2). Right ventricular systolic pressure (RVSP) did not change over time (36 mm Hg baseline, 37.5 mm Hg by 3 months, and 37 mm Hg by 1 year). One-year and 5-year survival were 93% and 73%, respectively. Postimplantation TR was an independent risk factor for late death (P < 0.05). CONCLUSION: Cardiac device implantation was associated with a small but significant increase in the prevalence of moderate and severe TR, both acutely and chronically after implantation. The increase in TR was similar with both ICD and PPM placement, which was not related to the number of leads implanted and not associated with a significant increase in RVSP. Postimplantation TR was associated with a higher risk of mortality.

The Effect of Beta-Blocker Post-Myocardial Infarction With Ejection Fraction >40% Pooled Analysis From Seven Arabian Gulf Acute Coronary Syndrome Registries.

The use of beta-blockers (BB) in reduced left ventricular ejection fraction (LVEF) post-myocardial infarction (MI) is associated with reduced 1-year mortality, while their role in patients with mid-range and preserved LVEF post-MI remains controversial. We studied 31,620 patients who presented with acute coronary syndrome (ACS) enrolled in seven Arabian Gulf registries between 2005 and 2017. Patients with LVEF ≤40% were excluded. The remaining cohort was divided into two groups: BB group (n = 15,541) and non-BB group (n = 2,798), based on discharge medications. Patients in the non-BB group were relatively younger (55.3 vs. 57.4, P = .004) but higher risk at presentation; with higher Global Registry of Acute Coronary Events (GRACE) score (119.2 vs 109.2, P < .001), higher percentage of cardiogenic shock (3.5 vs 1.4%, P < .001), despite lower prevalence of comorbidities, such as hypertension and hyperlipidemia. BB use was associated with lower 1-year mortality in a multivariate logistic regression analysis, adjusting for major confounders [adjusted odds ratio (OR): 0.71 (95% CI 0.51-0.99)]. This remained the case in a sensitivity analysis using propensity score matching [adjusted OR: 0.34 (95% CI 0.16-0.73)]. In this study, using Arabian Gulf countries registries, the use of BB after ACS with LVEF >40% was independently associated with lower 1-year mortality.

Cardiovascular Disease in Saudi Arabia: Facts and the Way Forward.

Cardiovascular diseases (CVDs) remain a major health concern globally. While some risk factors for CVDs are non-modifiable, other determinants like obesity, hypertension, type-2 diabetes and dyslipidemia can be mitigated by a wide plethora of measures to control CVD morbidity and mortality. Those determinants have been on the rise in Saudi Arabia, exacerbated by sedentary lifestyle. The Saudi Vision 2030 aims to reduce CVD clinical and economic burden and to scale up vitality and longevity; in a new era of comprehensive healthcare. From a health economics standpoint, CVDs entail a burden on healthcare systems directly through expenditure and indirectly through years living with the disease, low productivity, premature morbidity and mortality. This manuscript reviews current CV health and unmet needs in Saudi Arabia, discusses G20 countries' initiatives on primary prevention: public health measures, awareness programs; and proposes national registries and digital solutions to facilitate population-specific research, improve CV surveillance and alleviate CVD burden in Saudi Arabia.

Outcomes of atherectomy in patients undergoing lower extremity revascularisation.

BACKGROUND: There is a paucity of real-world data on the in-hospital (IH) and post-discharge outcomes in patients undergoing lower extremity peripheral vascular intervention (PVI) with adjunctive atherectomy. AIMS: In this retrospective, registry-based study, we evaluated IH and post-discharge outcomes among patients undergoing PVI, treated with or without atherectomy, in the National Cardiovascular Data Registry PVI Registry. METHODS: The IH composite endpoint included procedural complications, bleeding or thrombosis. The primary out-of-hospital endpoint was major amputation at 1 year. Secondary endpoints included repeat endovascular or surgical revascularisation and death. Multivariable regression was used to identify predictors of atherectomy use and its association with clinical endpoints. RESULTS: A total of 30,847 patients underwent PVI from 2014 to 2019, including 10,971 (35.6%) treated with atherectomy. The unadjusted rate of the IH endpoint occurred in 524 (4.8%) of the procedures involving atherectomy and 1,041 (5.3%) of non-atherectomy procedures (p=0.07). After adjustment, the use of atherectomy was not associated with an increased risk of the combined IH endpoint (p=0.68). In the 6,889 (22.4%) patients with out-of-hospital data, atherectomy was associated with a reduced risk of amputation (adjusted hazard ratio [aHR] 0.67, 95% confidence interval [CI]: 0.51-0.85; p<0.01) and surgical revascularisation (aHR 0.63, 95% CI: 0.44-0.89; p=0.017), no difference in death rates (p=0.10), but an increased risk of endovascular revascularisation (aHR 1.21, 95% CI: 1.06-1.39; p<0.01) at 1 year. CONCLUSIONS: The use of atherectomy during PVI is common and is not associated with an increase in IH adverse events. Longitudinally, patients treated with atherectomy undergo repeat endovascular reintervention more frequently but experience a reduced risk of amputation and surgical revascularisation.

Optimising PCI by Intracoronary Image-guidance.

Evidence to support the use of intracoronary imaging (ICI) in guiding percutaneous coronary intervention (PCI) is growing, with observational and randomized controlled trials demonstrating a benefit in acute procedural and clinical outcomes. ICI provides an opportunity to guide PCI, detailing the nature of the coronary disease, potentially influencing lesion preparation and stent selection. Following stent deployment, ICI offers a detailed assessment of lesion coverage, associated vessel trauma and stent expansion. Consensus statements have emphasized the role of ICI and detailed the parameters of stent optimization. However, intracoronary imaging is not adopted widely yet. Significant global differences in the uptake of ICI have been reported, with the vast majority of PCI being angiographically-guided. The three major barriers to the implementation of ICI include, in order of impact, prohibitive cost, prolongation of procedure time and local regulatory issues for use. However, it is our belief that a lack of education and the associated challenges of ICI interpretation provide the greatest barrier to adoption. We hope that this review of the role of ICI in PCI optimization will provide a platform for PCI operators to gain confidence in the utilization of ICI to enhance outcomes for their patients.

Association of Pulmonary Hypertension With Clinical Outcomes of Transcatheter Mitral Valve Repair.

Importance: Pulmonary hypertension (pHTN) is associated with increased risk of mortality after mitral valve surgery for mitral regurgitation. However, its association with clinical outcomes in patients undergoing transcatheter mitral valve repair (TMVr) with a commercially available system (MitraClip) is unknown. Objective: To assess the association of pHTN with readmissions for heart failure and 1-year all-cause mortality after TMVr. Design, Setting, and Participants: This retrospective cohort study analyzed 4071 patients who underwent TMVr with the MitraClip system from November 4, 2013, through March 31, 2017, across 232 US sites in the Society of Thoracic Surgery/American College of Cardiology Transcatheter Valve Therapy registry. Patients were stratified into the following 4 groups based on invasive mean pulmonary arterial pressure (mPAP): 1103 with no pHTN (mPAP, <25 mm Hg [group 1]); 1399 with mild pHTN (mPAP, 25-34 mm Hg [group 2]); 1011 with moderate pHTN (mPAP, 35-44 mm Hg [group 3]); and 558 with severe pHTN (mPAP, ≥45 mm Hg [group 4]). Data were analyzed from November 4, 2013, through March 31, 2017. Interventions: Patients were stratified into groups before TMVr, and clinical outcomes were assessed at 1 year after intervention. Main Outcomes and Measures: Primary end point was a composite of 1-year mortality and readmissions for heart failure. Secondary end points were 30-day and 1-year mortality and readmissions for heart failure. Linkage to Centers for Medicare & Medicaid Services administrative claims was performed to assess 1-year outcomes in 2381 patients. Results: Among the 4071 patients included in the analysis, the median age was 81 years (interquartile range, 73-86 years); 1885 (46.3%) were women and 2186 (53.7%) were men. The composite rate of 1-year mortality and readmissions for heart failure was 33.6% (95% CI, 31.6%-35.7%), which was higher in those with pHTN (27.8% [95% CI, 24.2%-31.5%] in group 1, 32.4% [95% CI, 29.0%-35.8%] in group 2, 36.0% [95% CI, 31.8%-40.2%] in group 3, and 45.2% [95% CI, 39.1%-51.0%] in group 4; P < .001). Similarly, 1-year mortality (16.3% [95% CI, 13.4%-19.5%] in group 1, 19.8% [95% CI, 17.0%-22.8%] in group 2, 22.4% [95% CI, 18.8%-26.1%] in group 3, and 27.8% [95% CI, 22.6%-33.3%] in group 4; P < .001) increased across pHTN groups. The association of pHTN with mortality persisted despite multivariable adjustment (hazard ratio per 5-mm Hg mPAP increase, 1.05; 95% CI, 1.01-1.09; P = .02). Conclusions and Relevance: These findings suggest that pHTN is associated with increased mortality and readmission for heart failure in patients undergoing TMVr using the MitraClip system for severe mitral regurgitation. Further efforts are needed to determine whether earlier intervention before pHTN develops will improve clinical outcomes.

Effect of Residual Interatrial Shunt on Migraine Burden After Transcatheter Closure of Patent Foramen Ovale.

OBJECTIVES: This study sought to evaluate the long-term effect of transcatheter patent foramen ovale (PFO) closure on migraineurs with and without aura and examine the effect of residual right-to-left shunt. BACKGROUND: Many studies reported improvement in migraine symptoms after PFO closure, yet randomized trials failed to reach its clinical endpoints. METHODS: The study retrospectively analyzed data from 474 patients who underwent transcatheter PFO closure at Massachusetts General Hospital. Patients completed a migraine burden questionnaire at baseline and at follow-up. Migraine severity is reported as migraine frequency (days/month), average duration (min), and migraine burden (days × min/month). Improvement following closure was defined as complete abolishment of symptoms or >50% reduction in migraine burden. RESULTS: A total of 110 migraineurs who underwent PFO closure were included; 77.0% had aura and 23.0% were without aura, and 91.0% had a cryptogenic stroke. During long-term median follow-up of 3.2 (interquartile range: 2.1 to 4.9) years, there was a significant improvement in migraine symptoms in migraineurs with or without aura. Migraine burden was reduced by >50% in 87.0% of patients, and symptoms were completely abolished in 48%. Presence of aura was associated with abolishment of migraine (odds ratio: 4.30; 95% confidence interval: 1.50 to 12.30; p = 0.006). At 6 months after PFO closure, residual right-to-left shunt was present in 26% of patients. Absence of right-to-left shunt was associated with improvement in migraine burden by >50% (odds ratio: 4.60; 95% confidence interval: 1.30 to 16.10; p = 0.017). CONCLUSIONS: Long-term follow-up after transcatheter PFO closure was associated with significant improvement in migraine burden. Aura was a predictor of abolishing symptoms. Absence of residual right-to-left shunt was a predictor of significant reduction in migraine burden.

Pulmonary Hypertension in Patients Eligible for Transcatheter Mitral Valve Repair: Prognostic Impact and Clinical Implications.

PURPOSE OF REVIEW: Transcatheter edge-to-edge mitral valve repair (TMVr) has been increasingly used in the treatment of patients with severe symptomatic mitral regurgitation who are at high or prohibitive risk for surgical intervention. Pre-existing pulmonary hypertension is known to pertain worse prognosis for patients who are undergoing surgical intervention. The aim of this review is to discuss the current literature on the effects of pulmonary hypertension on the transcatheter edge-to-edge mitral valve repair outcomes. RECENT FINDINGS: Large registry data in patients undergoing TMVr for treatment of severe mitral regurgitation reveal a significant negative impact of baseline pulmonary hypertension on post-procedural outcomes. Pulmonary hypertension is associated with increased mortality and heart failure readmissions in patients undergoing TMVr using MitraClip. Further prospective studies are needed to determine whether earlier intervention will improve clinical outcomes.

Comparison of Emergency Department Patients to Inpatients Receiving a Pulmonary Embolism Response Team (PERT) Activation.

OBJECTIVES: The development of pulmonary embolism response teams (PERTs) has been widely adopted nationally with the goal of providing multidisciplinary care to patients with high-risk PE. Most PERT activations originate from the emergency department (ED), while others are from the intensive care unit (ICU) or inpatient floors. It is unclear if ED PERT activations differ from non-ED PERT activation in terms of presentation, management, and outcome. METHODS: We enrolled a consecutive cohort of patients for whom PERT was activated at an urban academic medical center. We compared three groups of PERT activations based on whether the activation originated from the ED, ICU, or a non-ICU inpatient floor. We compared these groups in terms of the proportion of PERT activations that occurred during day, evening, or weekend hours and the proportion of confirmed PE. We also compared PE severity, treatment, and outcomes across locations. We tested differences using chi-square tests, with a two-tailed p-value of <0.05 considered statistically significant. RESULTS: We enrolled 561 patients, of whom 449 (79.5%) had confirmed PE. The mean ± SD age of patients with confirmed PE was 61 ± 17 years, and 300 (53.5%) were male. Activations from the ED (n = 283, 88.4%) or floor (n = 100, 74.6%) were more likely to be for confirmed PE than activations from the ICU (n = 63, 58.9%; p < 0.0001). There was a statistical difference in the time of day of PERT activation with the ED having more activations during night hours than the ICU or floors (p = 0.004). Most activations for confirmed, massive PE originated from the ICU (n = 41, 65.1%), followed by the ED (n = 82, 29%) and inpatient floors (n = 22, 22%; p < 0.0001). Most activations from the ED (n = 155, 54.8%) and floors (n = 55, 55%) were for submassive PE. The use of thrombolysis or thrombectomy was more common among ICU patients (n = 18, 33.3%), followed by ED patients (n = 53, 19.6%) and then floor patients (n = 8, 8.2%). Mortality and major bleeding events were most common among ICU patients and similar among ED and floor patients. CONCLUSIONS: Pulmonary embolism response team activations from different clinical locations differ in terms of patient presentation, PE confirmation, treatments, and outcomes. PERTs should be customized to support the different needs of each clinical area.

Radiofrequency Ablation of Persistent Atrial Fibrillation: Diagnosis-to-Ablation Time, Markers of Pathways of Atrial Remodeling, and Outcomes.

BACKGROUND: Various ablation strategies of persistent atrial fibrillation (PersAF) have had disappointing outcomes, despite concerted clinical and research efforts, which could reflect progressive atrial fibrillation-related atrial remodeling. METHODS AND RESULTS: Two-year outcomes were assessed in 1241 consecutive patients undergoing first-time ablation of PersAF (2005-2012). The time intervals between the first diagnosis of PersAF and the ablation procedures were determined. Patients had echocardiograms and measures of B-type natriuretic peptide and C-reactive protein before the procedures. The median diagnosis-to-ablation time was 3 years (25th-75th percentiles 1-6.5). With longer diagnosis-to-ablation time (based on quartiles), there was a significant increase in recurrence rates in addition to an increase in B-type natriuretic peptide levels (P=0.01), C-reactive protein levels (P<0.0001), and left atrial size (P=0.03). The arrhythmia recurrence rates over 2 years were 33.6%, 52.6%, 57.1%, and 54.6% in the first, second, third, and fourth quartiles, respectively (P(categorical)<0.0001). In Cox Proportional Hazard analyses, B-type natriuretic peptide levels, C-reactive protein levels, and left atrial size were associated with arrhythmia recurrence. The diagnosis-to-ablation time had the strongest association with the ablation outcomes which persisted in multivariable Cox analyzes (hazard ratio for recurrence per +1Log diagnosis-to-ablation time 1.27, 95% confidence interval 1.14-1.43; P<0.0001; hazard ratio fourth versus first quartile 2.44, 95% confidence interval 1.68-3.65; P(categorical)<0.0001). CONCLUSIONS: In patients with PersAF undergoing ablation, the time interval between the first diagnosis of PersAF and the catheter ablation procedure had a strong association with the ablation outcomes, such as shorter diagnosis-to-ablation times were associated with better outcomes and in direct association with markers of atrial remodeling.

Francisella tularensis: possible agent in bioterrorism.

Francisella tularensis, the causative agent of tularemia, is a highly infectious gram-negative coccobacillus. Due to its high infectivity it is of major concern to public health officials as a possible biological weapon. Although accidental exposure can occur through arthropod bites, handling infected animals, or breathing in aerosols, cases are usually isolated and contained. In the event of an intentional exposure such as in a bioterrorist attack, inhalation of aerosols can result in devastating consequences with much causality. Although a vaccine is available, sufficient quantities may not be readily accessible in an actual attack. Therefore, it is very important for both medical professionals and public health officials to be prepared to contain and control the situation should it actually occur.

Tricuspid regurgitation in patients with pacemakers and implantable cardiac defibrillators: a comprehensive review.

Implantable cardiac devices, including defibrillators and pacemakers, may be the cause of tricuspid regurgitation (TR) or may worsen existing TR. This review of the literature suggests that TR usually occurs over time after lead implantation. Diagnosis by clinical exam and 2-dimensional echocardiography may be augmented by 3-dimensional echocardiography and/or computed tomography. The mechanism may be mechanical perforation or laceration of leaflets, scarring and restriction of leaflets, or asynchronized activation of the right ventricle. Pacemaker-related TR might cause severe right-sided heart failure, but data regarding associated mortality are lacking. This comprehensive review summarizes the data regarding incidence, mechanism, and treatment of lead-related TR.

Cross-cultural comparison of the patient-centeredness of the hidden curriculum between a Saudi Arabian and 9 US medical schools.

BACKGROUND: The implicit "hidden curriculum" strongly influences medical students' perceptions of the importance of patient-centeredness. A new instrument, the Communication, Curriculum, and Culture Survey (C3), already used to assess this hard-to- access part of the curriculum in the US, has potential for use in cross-cultural comparisons. OBJECTIVE: To use the C3 to perform a pilot cross-cultural comparison of the patient-centeredness of the hidden curriculum between a Saudi medical school and 9 U.S. medical schools. DESIGN: Senior Saudi medical students completed the C3 and a second instrument, the Patient-Provider Orientation Scale (PPOS), which measured their attitudes toward patient-centered behavior. PARTICIPANTS: Senior Saudi medical students. RESULTS: 139/256 (54%) Saudis completed the C3; 122/256(48%) completed the PPOS. Means for 2 out of 3 of the C3's domains (0-100 scale) were lower for the Saudis than those for the Americans (95% confidence intervals in parentheses): 47 (45, 50) vs. 55 (53, 58); 54 (50, 58) vs. 68 (67, 70); they overlapped in the third: 60 (57, 63) vs. 62 (60, 63). The mean Saudi PPOS score was 4.0 (3.9, 4.1); for the American medical schools, 4.8 (4.8-4.8) (1-6, least to most patient-centered). CONCLUSIONS: In this preliminary study the data suggest that the patient-centeredness of the hidden curriculum differs in Saudi and US medical schools in 2 out of 3 domains. Cross-cultural use of instruments such as the C3 can highlight such important differences and help educators evaluate their curriculum from an international, as well as a local perspective. Use of instruments across borders is a growing trend and an indicator of the increasing globalization of medical education.