Association of Lipoprotein (a) and Standard Modifiable Cardiovascular Risk Factors With Incident Myocardial Infarction: The Mass General Brigham Lp(a) Registry.

BACKGROUND: Lipoprotein (a) [Lp(a)] is a robust predictor of coronary heart disease outcomes, with targeted therapies currently under investigation. We aimed to evaluate the association of high Lp(a) with standard modifiable risk factors (SMuRFs) for incident first acute myocardial infarction (AMI). METHODS AND RESULTS: This retrospective study used the Mass General Brigham Lp(a) Registry, which included patients aged ≥18 years with an Lp(a) measurement between 2000 and 2019. Exclusion criteria were severe kidney dysfunction, malignant neoplasm, and prior known atherosclerotic cardiovascular disease. Diabetes, dyslipidemia, hypertension, and smoking were considered SMuRFs. High Lp(a) was defined as >90th percentile, and low Lp(a) was defined as <50th percentile. The primary outcome was fatal or nonfatal AMI. A combination of natural language processing algorithms, International Classification of Diseases (ICD) codes, and laboratory data was used to identify the outcome and covariates. A total of 6238 patients met the eligibility criteria. The median age was 54 (interquartile range, 43-65) years, and 45% were women. Overall, 23.7% had no SMuRFs, and 17.8% had ≥3 SMuRFs. Over a median follow-up of 8.8 (interquartile range, 4.2-12.8) years, the incidence of AMI increased gradually, with higher number of SMuRFs among patients with high (log-rank P=0.031) and low Lp(a) (log-rank P<0.001). Across all SMuRF subgroups, the incidence of AMI was significantly higher for patients with high Lp(a) versus low Lp(a). The risk of high Lp(a) was similar to having 2 SMuRFs. Following adjustment for confounders and number of SMuRFs, high Lp(a) remained significantly associated with the primary outcome (hazard ratio, 2.9 [95% CI, 2.0-4.3]; P<0.001). CONCLUSIONS: Among patients with no prior atherosclerotic cardiovascular disease, high Lp(a) is associated with significantly higher risk for first AMI regardless of the number of SMuRFs.

Prognostic value of myocardial flow reserve vs corrected myocardial flow reserve in patients without obstructive coronary artery disease.

BACKGROUND: Myocardial flow reserve (MFR) by positron emission tomography (PET) is a validated measure of cardiovascular risk. Elevated resting rate pressure product (RPP = heart rate x systolic blood pressure) can cause high resting myocardial blood flow (MBF), resulting in reduced MFR despite normal/near-normal peak stress MBF. When resting MBF is high, it is not known if RPP-corrected MFR (MFRcorrected) helps reclassify CV risk. We aimed to study this question in patients without obstructive coronary artery disease (CAD). METHODS: We retrospectively studied patients referred for rest/stress cardiac PET at our center from 2006 to 2020. Patients with abnormal perfusion (summed stress score >3) or prior coronary artery bypass grafting (CABG) were excluded. MFRcorrected was defined as stress MBF/corrected rest MBF where corrected rest MBF = rest MBF x 10,000/RPP. The primary outcome was major cardiovascular events (MACE): cardiovascular death or myocardial infarction. Associations of MFR and MFRcorrected with MACE were assessed using unadjusted and adjusted Cox regression. RESULTS: 3276 patients were followed for a median of 7 (IQR 3-12) years. 1685 patients (51%) had MFR <2.0, and of those 366 (22%) had an MFR ≥2.0 after RPP correction. MFR <2.0 was associated with an increased absolute risk of MACE (HR 2.24 [1.79-2.81], P < 0.0001). Among patients with MFR <2.0, the risk of MACE was not statistically different between patients with an MFRcorrected ≥2.0 compared with those with MFRcorrected <2.0 (1.9% vs 2.3% MACE/year, HR 0.84 [0.63-1.13], P = 0.26) even after adjustment for confounders (P = 0.66). CONCLUSIONS: In patients without overt obstructive CAD and MFR< 2.0, there was no significant difference in cardiovascular risk between patients with discordant (≥2.0) and concordant (<2) MFR following RPP correction. This suggests that RPP-corrected MFR may not consistently provide accurate risk stratification in patients with normal perfusion and MFR <2.0. Stress MBF and uncorrected MFR should be reported to more reliably convey cardiovascular risk beyond perfusion results.

Lipoprotein(a) and Major Adverse Cardiovascular Events in Patients With or Without Baseline Atherosclerotic Cardiovascular Disease.

BACKGROUND: Lipoprotein(a) [Lp(a)] is associated with an increased risk of atherosclerotic cardiovascular disease (ASCVD). However, whether the optimal Lp(a) threshold for risk assessment should differ based on baseline ASCVD status is unknown. OBJECTIVES: The purpose of this study was to assess the association between Lp(a) and major adverse cardiovascular events (MACE) among patients with and without baseline ASCVD. METHODS: We studied a retrospective cohort of patients with Lp(a) measured at 2 medical centers in Boston, Massachusetts, from 2000 to 2019. To assess the association of Lp(a) with incident MACE (nonfatal myocardial infarction [MI], nonfatal stroke, coronary revascularization, or cardiovascular mortality), Lp(a) percentile groups were generated with the reference group set at the first to 50th Lp(a) percentiles. Cox proportional hazards modeling was used to assess the association of Lp(a) percentile group with MACE. RESULTS: Overall, 16,419 individuals were analyzed with a median follow-up of 11.9 years. Among the 10,181 (62%) patients with baseline ASCVD, individuals in the 71st to 90th percentile group had a 21% increased hazard of MACE (adjusted HR: 1.21; P < 0.001), which was similar to that of individuals in the 91st to 100th group (adjusted HR: 1.26; P < 0.001). Among the 6,238 individuals without established ASCVD, there was a continuously higher hazard of MACE with increasing Lp(a), and individuals in the 91st to 100th Lp(a) percentile group had the highest relative risk with an adjusted HR of 1.93 (P < 0.001). CONCLUSIONS: In a large, contemporary U.S. cohort, elevated Lp(a) is independently associated with long-term MACE among individuals with and without baseline ASCVD. Our results suggest that the threshold for risk assessment may be different in primary vs secondary prevention cohorts.

Artificial Intelligence in Coronary Artery Calcium Scoring Detection and Quantification.

Coronary artery calcium (CAC) is a marker of coronary atherosclerosis, and the presence and severity of CAC have been shown to be powerful predictors of future cardiovascular events. Due to its value in risk discrimination and reclassification beyond traditional risk factors, CAC has been supported by recent guidelines, particularly for the purposes of informing shared decision-making regarding the use of preventive therapies. In addition to dedicated ECG-gated CAC scans, the presence and severity of CAC can also be accurately estimated on non-contrast chest computed tomography scans performed for other clinical indications. However, the presence of such "incidental" CAC is rarely reported. Advances in artificial intelligence have now enabled automatic CAC scoring for both cardiac and non-cardiac CT scans. Various AI approaches, from rule-based models to machine learning algorithms and deep learning, have been applied to automate CAC scoring. Convolutional neural networks, a deep learning technique, have had the most successful approach, with high agreement with manual scoring demonstrated in multiple studies. Such automated CAC measurements may enable wider and more accurate detection of CAC from non-gated CT studies, thus improving the efficiency of healthcare systems to identify and treat previously undiagnosed coronary artery disease.

Comparative Effectiveness of PET and SPECT MPI for Predicting Cardiovascular Events After Kidney Transplant.

BACKGROUND: Advanced chronic kidney disease is associated with high cardiovascular risk, even after kidney transplant. Pretransplant cardiac testing may identify patients who require additional assessment before transplant or would benefit from risk optimization. The objective of the current study was to determine the relative prognostic utility of pretransplant positron emission tomography (PET) and single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) for posttransplant major adverse cardiovascular events (MACEs). METHODS: We retrospectively followed patients who underwent MPI before kidney transplant for the occurrence of MACE after transplant including myocardial infarction, stroke, heart failure, and cardiac death. An abnormal MPI result was defined as a total perfusion deficit >5% of the myocardium. To determine associations of MPI results with MACE, we utilized Cox hazard regression with propensity weighting for PET versus SPECT with model factors, including demographics and cardiovascular risk factors. RESULTS: A total of 393 patients underwent MPI (208 PET and 185 SPECT) and were followed for a median of 5.9 years post-transplant. Most were male (58%), median age was 58 years, and there was a high burden of hypertension (88%) and diabetes (33%). A minority had abnormal MPI (n=58, 15%). In propensity-weighted hazard regression, abnormal PET result was associated with posttransplant MACE (hazard ratio, 3.02 [95% CI, 1.78-5.11]; P<0.001), while there was insufficient evidence of an association of abnormal SPECT result with MACE (1.39 [95% CI, 0.72-2.66]; P=0.33). The explained relative risk of the PET result was higher than the SPECT result (R2 0.086 versus 0.007). Normal PET was associated with the lowest risk of MACE (2.2%/year versus 3.6%/year for normal SPECT; P<0.001). CONCLUSIONS: Kidney transplant recipients are at high cardiovascular risk, despite a minority having obstructive coronary artery disease on MPI. PET MPI findings predict posttransplant MACE. Normal PET may better discriminate lower risk patients compared with normal SPECT, which should be confirmed in a larger prospective study.

Coronary Microcirculatory Dysfunction in People With HIV and Its Association With Antiretroviral Therapy.

BACKGROUND: HIV infection and abacavir-containing antiretroviral regimens are associated with vascular endothelial dysfunction and increased cardiovascular risk. Positron emission tomography (PET)-derived myocardial blood flow reserve (MBFR), the ratio of vasodilator stress to rest myocardial blood flow, is a well-validated measure of coronary microvascular health and marker of cardiovascular risk. Our objective was to compare MBFR among people with HIV (PWH) with matched non-HIV controls and to assess whether switching from dolutegravir/lamivudine/abacavir to the non-abacavir regimen bictegravir/emtricitabine/tenofovir alafenamide (TAF) would improve MBFR. METHODS AND RESULTS: Thirty-seven PWH were 1:2 matched on cardiovascular risk factors to 75 people without HIV, and MBFR corrected for differences in resting hemodynamics was compared in a cross-sectional design. PWH were majority men (68%) with a mean age of 56 years. Mean stress myocardial blood flow (1.83 mL/min per g [95% CI, 1.68-1.98] versus 2.40 mL/min per g [95% CI, 2.25-2.54]; P<0.001) and MBFR (2.18 [95% CI, 1.96-2.40] versus 2.68 [95% CI, 2.47-2.89]; P=0.002) was significantly lower in PWH than in people without HIV. In a single-arm, multicenter trial, a subset of 25 PWH who were virologically suppressed on dolutegravir/lamivudine/abacavir underwent positron emission tomography myocardial perfusion imaging at baseline and after switching to bictegravir/emtricitabine/TAF. MBFR was unchanged after switching to bictegravir/emtricitabine/TAF for a mean of 27 weeks (MBFR, 2.34 to 2.29; P=0.61), except in PWH with impaired MBFR at baseline (<2.00; N=6) in whom MBFR increased from 1.58 to 2.02 (P=0.02). CONCLUSIONS: PWH had reduced coronary microvascular function compared with controls without HIV. Coronary microvascular function did not improve after switching from dolutegravir/lamivudine/abacavir to bictegravir/emtricitabine/TAF. REGISTRATION: URL: https://www.clinicaltrials.gov; unique identifier: NCT03656783.

Targeting pharmacotherapies for inflammatory and cardiorenal endpoints in kidney disease.

ABSTRACT: Inflammation is an important contributor to excess cardiovascular risk and progressive renal injury in people with CKD. Dysregulation of the innate and adaptive immune system is accelerated by CKD and results in increased systemic inflammation, a heightened local vascular inflammatory response leading to accelerated atherosclerosis, and dysfunction of the cardiac and renal endothelium and microcirculation. Understanding and addressing the dysregulated immune system is a promising approach to modifying cardiorenal outcomes in people with CKD. However, targeted pharmacotherapies adopted from trials of non-CKD and cardio-rheumatology populations are only beginning to be developed and tested in human clinical trials. Pharmacotherapies that inhibit activation of the NLRP3 inflammasome and the downstream cytokines IL-1 and IL-6 are the most well-studied. However, most of the available evidence for efficacy is from small clinical trials with inflammatory and cardiorenal biomarker endpoints, rather than cardiovascular event endpoints, or from small CKD subgroups in larger clinical trials. Other pharmacotherapies that have proven beneficial for cardiorenal endpoints in people with CKD have been found to have pleiotropic anti-inflammatory benefits including statins, mineralocorticoid receptor antagonists, SGLT-2 inhibitors, and GLP-1 agonists. Finally, emerging therapies in CKD such as IL-6 inhibition, small-interfering RNA against lipoproteins, AhR inhibitors, and therapies adopted from the renal transplant population including mTOR inhibitors and T regulatory cell promoters may have benefits for cardiorenal and inflammatory endpoints but require further investigation in clinical trials.

Cardiovascular outcomes in patients with coronary artery disease and elevated lipoprotein(a): implications for the OCEAN(a)-outcomes trial population.

Aims: The ongoing Olpasiran Trials of Cardiovascular Events and Lipoprotein(a) Reduction [OCEAN(a)]-Outcomes trial is evaluating whether Lp(a) lowering can reduce the incidence of cardiovascular events among patients with prior myocardial infarction (MI) or percutaneous coronary intervention (PCI) and elevated Lp(a) (≥200 nmol/L). The purpose of this study is to evaluate the association of elevated Lp(a) with cardiovascular outcomes in an observational cohort resembling the OCEAN(a)-Outcomes trial main enrolment criteria. Methods and results: This study included patients aged 18-85 years with Lp(a) measured as part of their clinical care between 2000 and 2019. While patients were required to have a history of MI, or PCI, those with severe kidney dysfunction or a malignant neoplasm were excluded. Elevated Lp(a) was defined as ≥200 nmol/L consistent with the OCEAN(a)-Outcomes trial. The primary outcome was a composite of coronary heart disease death, MI, or coronary revascularization. Natural language processing algorithms, billing and ICD codes, and laboratory data were employed to identify outcomes and covariates. A total of 3142 patients met the eligibility criteria, the median age was 61 (IQR: 52-73) years, 28.6% were women, and 12.3% had elevated Lp(a). Over a median follow-up of 12.2 years (IQR: 6.2-14.3), the primary composite outcome occurred more frequently in patients with versus without elevated Lp(a) [46.0 vs. 38.0%, unadjHR = 1.30 (95% CI: 1.09-1.53), P = 0.003]. Following adjustment for measured confounders, elevated Lp(a) remained independently associated with the primary outcome [adjHR = 1.33 (95% CI: 1.12-1.58), P = 0.001]. Conclusion: In an observational cohort resembling the main OCEAN(a)-Outcomes Trial enrolment criteria, patients with an Lp(a) ≥200 nmol/L had a higher risk of cardiovascular outcomes.

Randomized Placebo-Controlled Trial to Evaluate Effects of Eplerenone on Myocardial Perfusion and Function Among Persons With Human Immunodeficiency Virus (HIV)-Results From the MIRACLE HIV Study.

BACKGROUND: Increased renin angiotensin aldosterone system (RAAS) activity may contribute to excess cardiovascular disease in people with HIV (PWH). We investigated how RAAS blockade may improve myocardial perfusion, injury, and function among well-treated PWH. METHODS: Forty PWH, on stable ART, without known heart disease were randomized to eplerenone 50 mg PO BID (n = 20) or identical placebo (n = 20) for 12 months. The primary endpoints were (1) myocardial perfusion assessed by coronary flow reserve (CFR) on cardiac PET or stress myocardial blood flow (sMBF) on cardiac MRI or (2) myocardial inflammation by extracellular mass index (ECMi) on cardiac MRI. RESULTS: Beneficial effects on myocardial perfusion were seen for sMBF by cardiac MRI (mean [SD]: 0.09 [0.56] vs -0.53 [0.68] mL/min/g; P = .03) but not CFR by cardiac PET (0.01 [0.64] vs -0.07 [0.48]; P = .72, eplerenone vs placebo). Eplerenone improved parameters of myocardial function on cardiac MRI including left ventricular end diastolic volume (-13 [28] vs 10 [26] mL; P = .03) and global circumferential strain (GCS; median [interquartile range 25th-75th]: -1.3% [-2.9%-1.0%] vs 2.3% [-0.4%-4.1%]; P = .03), eplerenone versus placebo respectively. On cardiac MRI, improvement in sMBF related to improvement in global circumferential strain (ρ = -0.65, P = .057) among those treated with eplerenone. Selecting for those with impaired myocardial perfusion (CFR <2.5 and/or sMBF <1.8), there was a treatment effect of eplerenone versus placebo to improve CFR (0.28 [0.27] vs -0.05 [0.36]; P = .04). Eplerenone prevented a small increase in troponin (0.00 [-0.13-0.00] vs 0.00 [0.00-0.74] ng/L; P = .03) without effects on ECMi (0.9 [-2.3-4.3] vs -0.7 [-2.2--0.1] g/m2; P = .38). CD4+ T-cell count (127 [-38-286] vs -6 [-168-53] cells/µL; P = .02) increased in the eplerenone- versus placebo-treated groups. CONCLUSIONS: RAAS blockade with eplerenone benefitted key indices and prevented worsening of myocardial perfusion, injury, and function among PWH with subclinical cardiac disease when compared with placebo. CLINICAL TRIALS REGISTRATION: NCT02740179 (https://clinicaltrials.gov/ct2/show/NCT02740179?term=NCT02740179&draw=2&rank=1).

Prior SARS-CoV-2 Infection Is Associated With Coronary Vasomotor Dysfunction as Assessed by Coronary Flow Reserve From Cardiac Positron Emission Tomography.

Background Cardiovascular complications from COVID-19 contribute to its high morbidity and mortality. The effect of COVID-19 infection on the coronary vasculature is not known. The objective of this study was to investigate the prevalence of coronary vasomotor dysfunction identified by coronary flow reserve from cardiac positron emission tomography in patients with previous COVID-19 infection. Methods and Results All patients who had polymerase chain reaction-confirmed SARS-CoV-2 infection referred for myocardial stress perfusion positron emission tomography imaging at Brigham and Women's Hospital from April 2020 to July 2021 were compared with a matched control group without prior SARS-CoV-2 infection imaged in the same period. The main outcome was the prevalence of coronary vasomotor dysfunction. Myocardial perfusion and myocardial blood flow reserve were quantified using N13-ammonia positron emission tomography imaging. Thirty-four patients with prior COVID-19 were identified and compared with 103 matched controls. The median time from polymerase chain reaction-confirmed SARS-CoV-2 to cardiac positron emission tomography was 4.6 months (interquartile range,1.2-5.6 months). There were 16 out of 34 (47%) patients previously hospitalized for COVID-19 infection. Baseline cardiac risk factors were common, and 18 (53%) patients in the COVID-19 group had abnormal myocardial perfusion. Myocardial blood flow reserve was abnormal (<2) in 44.0% of the patients with COVID-19 compared with 11.7% of matched controls (P<0.001). The mean myocardial blood flow reserve was 19.4% lower in patients with COVID-19 compared with control patients (2.00±0.45 versus 2.48±0.47, P<0.001). Conclusions Myocardial blood flow reserve was impaired in patients with prior COVID-19 infection compared with cardiovascular risk factor-matched controls, suggesting a relationship between SARS-CoV-2 infection and coronary vascular health. These data highlight the need to assess long-term consequences of COVID-19 on vascular health in future prospective studies.

Nebivolol and incident cardiovascular events in hypertensive patients compared with nonvasodilatory beta blockers.

OBJECTIVE: Nonvasodilatory beta blockers are associated with inferior cardiovascular event reduction compared with other antihypertensive classes, and there is uncertainty about first-line use of beta blockers for hypertension in guidelines. The third generation vasodilatory beta blocker nebivolol has unique beneficial effects on central and peripheral vasculature. Our objective was to compare longitudinal cardiovascular outcomes of hypertensive patients taking nebivolol with those taking the nonvasodilatory beta blockers metoprolol and atenolol. METHODS: We performed a retrospective cohort analysis of hypertensive adults in the University of Colorado health system, without preceding diagnosis of cardiovascular or cerebrovascular disease. The primary outcome was composite incident heart failure, stroke, myocardial infarction, angina, or coronary revascularization. Mahalanobis 1:2 distance matching and Cox proportional hazards regression was used. Matching and regression variables included baseline demographics, socioeconomic factors, medical insurance type, prescribing provider type, cardiovascular risk factors, Charlson comorbidity index, other medications, and follow-up duration. RESULTS: After matching, patients were predominantly women (54%, 3085 of 5705) and non-Hispanic Caucasian (79%, 4534 of 5705), with median age of 58. In matched Cox regression analysis, nebivolol was associated with 17% reduction in incident cardiovascular events compared with all nonvasodilatory beta blockers [hazard ratio 0.83, 95% confidence interval (CI) 0.74-0.94, P  = 0.004], and 24% reduction compared with metoprolol (hazard ratio 0.76, CI 0.66-0.87, P = 0.0001). CONCLUSION: The vasodilatory beta blocker nebivolol was associated with reduced incident cardiovascular events compared with nonvasodilatory beta blockers. Additional study of other beta blockers is necessary to determine if this is a vasodilatory beta blocker class effect or is specific to nebivolol.http://links.lww.com/HJH/B916.

Carotid Artery Stiffness and Cognitive Decline Among Women With or at Risk for HIV Infection.

BACKGROUND: Vascular stiffness is associated with aging and cognitive impairment in older populations without HIV. HIV has been linked to increased vascular stiffness. We examined whether vascular stiffness relates to cognitive decline at younger ages in women with or at risk for HIV. METHODS: We evaluated the association of carotid artery stiffness with decline in neuropsychological test performance among participants in the Women's Interagency HIV Study and assessed whether HIV modified the association. Baseline carotid stiffness, defined by the distensibility index, was determined at a single visit using carotid artery ultrasound. Longitudinal neuropsychological testing from 2004-2016 included Trail Making Tests A and B and the Symbol Digit Modalities Test. Relationships were assessed with linear mixed-effect models adjusted for demographic, behavioral, cardiometabolic, and neuropsychological factors. RESULTS: Among 1662 women (1192 [72%] HIV+), median baseline age was 41 years (interquartile range 34-47), with 60% non-Hispanic black and 28% Hispanic. Lower baseline distensibility (greater carotid stiffness) was associated with greater decline in neuropsychological test scores over 10-year follow-up as measured by Symbol Digit Modalities Test (adjusted ß = -0.06 per SD, P < 0.001), Trail Making Test A (ß = -0.08 per SD; P < 0.001), and Trail Making Test B (ß = -0.08 per SD; P < 0.001). Changes in cognitive function did not differ by HIV serostatus, or HIV-related factors. CONCLUSIONS: Higher carotid stiffness was independently associated with faster decline in executive functioning, information processing, and psychomotor speed even in mostly middle-aged minority women and regardless of HIV serostatus. Our study highlights the need for cardiovascular risk factor modification to prevent premature cognitive deterioration in this at-risk population.

Role of Natural Autoantibodies in Ugandans With Rheumatic Heart Disease and HIV.

BACKGROUND: Rheumatic heart disease (RHD) and HIV are prevalent diseases in sub-Saharan Africa, but little is known about their potential interrelationships. The objective of this study was to assess the prevalence of protective natural autoantibodies among patients with RHD in Uganda, and to determine whether the levels of these autoantibodies are affected by HIV status. METHODS: Participants were grouped according to RHD and HIV status. The three control groups (RHD - HIV -, RHD - HIV +, RHD + HIV -) were age-matched to the RHD + HIV + participants. All participants underwent HIV testing and echocardiography to evaluate for RHD. Natural autoantibody levels reactive with phosphorylcholine (PC) and malondialdehyde (MDA) were measured. FINDINGS: We enrolled 220 participants; 21 with both RHD and HIV. Ages ranged from 10 to 60 years, with female predominance (144/220, 65%). After adjusting for age and gender, HIV infection and RHD were each associated with low IgM anti-PC (HIV: p < 0.0001 and RHD: p = 0.01). A distinct HIV ∗ RHD interaction was identified (p = 0.045) with increased IgG anti-MDA levels in HIV infected subjects without RHD, whereas IgG anti-MDA levels were decreased in HIV infected subjects with RHD. INTERPRETATION: We found that HIV and RHD are associated with alterations in natural autoantibody responses previously linked to an increased risk for atherosclerosis and autoimmune inflammatory disease.

A qualitative examination of secondary prophylaxis in rheumatic heart disease: factors influencing adherence to secondary prophylaxis in Uganda.

BACKGROUND: Rheumatic heart disease (RHD) is the most common cause of heart disease among Ugandans age 15 to 49 years. Secondary prophylaxis with monthly injection of benzathine penicillin is effective in preventing recurrence of acute rheumatic fever and worsening of RHD, but adherence rates are poor in Uganda. OBJECTIVES: This study sought to identify health behaviors, attitudes, and health care system factors that influence adherence to RHD secondary prophylaxis. METHODS: We conducted 5 structured focus groups with 36 participants on monthly penicillin injections for RHD in Kamplala, Uganda. Transcripts were analyzed using qualitative description analysis and health behavior models. RESULTS: Most participants were female (64%), from an urban area (81%), and had family income less than US$1 daily (69%). Ages ranged from 14 to 58 years. Median prophylaxis duration was 1.42 years and 58% were adherent (≥80% of injections). Key facilitators include perceived worsening of disease with missing injections, personal motivation, a reminder system for injections, supportive family and friends, and a positive relationship with health care providers. Barriers to adherence include lack of resources for transportation and medications, fear of injection pain, poor patient-provider communication, and poor availability of clinics and providers able to give injections. CONCLUSIONS: We identified key facilitators and barriers to secondary prophylaxis for RHD from the patient perspective framed within the socioecological model. Our findings provide direction for intervention development to improve national RHD secondary prophylaxis.