Intravascular lithotripsy in the treatment of coronary artery calcification in a high-risk real world population.

BACKGROUND: The DISRUPT-CAD study series demonstrated feasibility and safety of intravascular lithotripsy (IVL) in selected patients, but applicability across a broad range of clinical scenarios remains unclear. AIMS: This study aims to evaluate the procedural and clinical outcomes of IVL in a high-risk real-world cohort, compared to a regulatory approval cohort. METHODS: Consecutive patients treated with IVL and percutaneous coronary intervention at our center from May 2016 to April 2020 were included. Comparison was made between those enrolled in the DISRUPT-CAD series of studies to those with calcified lesions but an exclusion criteria. RESULTS: Among 177 patients treated with IVL, 142 were excluded from regulatory trials due to acute coronary syndrome presentation (47.2%), left ventricular ejection fraction <40% (22.5%), chronic renal failure (12.0%), or use of mechanical circulatory support (8.5%). This clinical cohort had a higher SYNTAX score (22.6 ± 12.1 vs. 17.4 ± 9.9, p = 0.019), and more treated ACC/AHA C lesions (56.3% vs. 37.1%, p = 0.042). Rates of device success (93.7% vs. 100.0%, p = 0.208), procedural success (96.5% vs. 100.0%, p = 0.585), and minimal lumen area gain (221.2 ± 93.7% vs. 198.6 ± 152.0%, p = 0.807) were similar in both groups. The DISRUPT-CAD cohort had no in-hospital mortality, 30-day major adverse cardiac events (MACE), or 30-day target vessel revascularization (TVR). The clinical cohort had an in-hospital mortality of 4.2%, 30-day MACE of 7.8%, and 30-day TVR of 1.5%. There was no difference in 12-month TVR (2.9% vs. 2.2%; p = 0.825). Twelve-month MACE was higher in the clinical cohort (21.1% vs. 8.6%, p = 0.03). CONCLUSION: IVL use remains associated with high clinical efficacy, procedural success, and low complication rates in a real-world population previously excluded from regulatory approving trials.

Mortality risk prediction of high-sensitivity C-reactive protein in suspected acute coronary syndrome: A cohort study.

BACKGROUND: There is limited evidence on the use of high-sensitivity C-reactive protein (hsCRP) as a biomarker for selecting patients for advanced cardiovascular (CV) therapies in the modern era. The prognostic value of mildly elevated hsCRP beyond troponin in a large real-world cohort of unselected patients presenting with suspected acute coronary syndrome (ACS) is unknown. We evaluated whether a mildly elevated hsCRP (up to 15 mg/L) was associated with mortality risk, beyond troponin level, in patients with suspected ACS. METHODS AND FINDINGS: We conducted a retrospective cohort study based on the National Institute for Health Research Health Informatics Collaborative data of 257,948 patients with suspected ACS who had a troponin measured at 5 cardiac centres in the United Kingdom between 2010 and 2017. Patients were divided into 4 hsCRP groups (<2, 2 to 4.9, 5 to 9.9, and 10 to 15 mg/L). The main outcome measure was mortality within 3 years of index presentation. The association between hsCRP levels and all-cause mortality was assessed using multivariable Cox regression analysis adjusted for age, sex, haemoglobin, white cell count (WCC), platelet count, creatinine, and troponin. Following the exclusion criteria, there were 102,337 patients included in the analysis (hsCRP <2 mg/L (n = 38,390), 2 to 4.9 mg/L (n = 27,397), 5 to 9.9 mg/L (n = 26,957), and 10 to 15 mg/L (n = 9,593)). On multivariable Cox regression analysis, there was a positive and graded relationship between hsCRP level and mortality at baseline, which remained at 3 years (hazard ratio (HR) (95% CI) of 1.32 (1.18 to 1.48) for those with hsCRP 2.0 to 4.9 mg/L and 1.40 (1.26 to 1.57) and 2.00 (1.75 to 2.28) for those with hsCRP 5 to 9.9 mg/L and 10 to 15 mg/L, respectively. This relationship was independent of troponin in all suspected ACS patients and was further verified in those who were confirmed to have an ACS diagnosis by clinical coding. The main limitation of our study is that we did not have data on underlying cause of death; however, the exclusion of those with abnormal WCC or hsCRP levels >15 mg/L makes it unlikely that sepsis was a major contributor. CONCLUSIONS: These multicentre, real-world data from a large cohort of patients with suspected ACS suggest that mildly elevated hsCRP (up to 15 mg/L) may be a clinically meaningful prognostic marker beyond troponin and point to its potential utility in selecting patients for novel treatments targeting inflammation. TRIAL REGISTRATION: ClinicalTrials.gov - NCT03507309.

Invasive versus non-invasive management of older patients with non-ST elevation myocardial infarction (SENIOR-NSTEMI): a cohort study based on routine clinical data.

BACKGROUND: Previous trials suggest lower long-term risk of mortality after invasive rather than non-invasive management of patients with non-ST elevation myocardial infarction (NSTEMI), but the trials excluded very elderly patients. We aimed to estimate the effect of invasive versus non-invasive management within 3 days of peak troponin concentration on the survival of patients aged 80 years or older with NSTEMI. METHODS: Routine clinical data for this study were obtained from five collaborating hospitals hosting NIHR Biomedical Research Centres in the UK (all tertiary centres with emergency departments). Eligible patients were 80 years old or older when they underwent troponin measurements and were diagnosed with NSTEMI between 2010 (2008 for University College Hospital) and 2017. Propensity scores (patients' estimated probability of receiving invasive management) based on pretreatment variables were derived using logistic regression; patients with high probabilities of non-invasive or invasive management were excluded. Patients who died within 3 days of peak troponin concentration without receiving invasive management were assigned to the invasive or non-invasive management groups based on their propensity scores, to mitigate immortal time bias. We estimated mortality hazard ratios comparing invasive with non-invasive management, and compared the rate of hospital admissions for heart failure. FINDINGS: Of the 1976 patients with NSTEMI, 101 died within 3 days of their peak troponin concentration and 375 were excluded because of extreme propensity scores. The remaining 1500 patients had a median age of 86 (IQR 82-89) years of whom (845 [56%] received non-invasive management. During median follow-up of 3·0 (IQR 1·2-4·8) years, 613 (41%) patients died. The adjusted cumulative 5-year mortality was 36% in the invasive management group and 55% in the non-invasive management group (adjusted hazard ratio 0·68, 95% CI 0·55-0·84). Invasive management was associated with lower incidence of hospital admissions for heart failure (adjusted rate ratio compared with non-invasive management 0·67, 95% CI 0·48-0·93). INTERPRETATION: The survival advantage of invasive compared with non-invasive management appears to extend to patients with NSTEMI who are aged 80 years or older. FUNDING: NIHR Imperial Biomedical Research Centre, as part of the NIHR Health Informatics Collaborative.

Direct cardiac versus systemic effects of inorganic nitrite on human left ventricular function.

Inorganic nitrite is a source of nitric oxide (NO) and is considered as a potential therapy in settings where endogenous NO bioactivity is reduced and left ventricular (LV) function impaired. However, the effects of nitrite on human cardiac contractile function, and the extent to which these are direct or indirect, are unclear. We studied 40 patients undergoing diagnostic cardiac catheterization who had normal LV systolic function and were not found to have obstructive coronary disease. They received either an intracoronary sodium nitrite infusion (8.7-26 µmol/min, n = 20) or an intravenous sodium nitrite infusion (50 µg/kg/min, n = 20). LV pressure-volume relations were recorded. The primary end point was LV end-diastolic pressure (LVEDP). Secondary end points included indices of LV systolic and diastolic function. Intracoronary nitrite infusion induced a significant reduction in LVEDP, LV end-diastolic pressure-volume relationship (EDPVR), and the time to LV end-systole (LVEST) but had no significant effect on LV systolic function or systemic hemodynamics. Intravenous nitrite infusion induced greater effects, with significant decreases in LVEDP, EDPVR, LVEST, LV dP/dtmin, tau, and mean arterial pressure. Inorganic nitrite has modest direct effects on human LV diastolic function, independent of LV loading conditions and without affecting LV systolic properties. However, the systemic administration of nitrite has larger effects on LV diastolic function, which are related to reduction in both preload and afterload. These contractile effects of inorganic nitrite may indicate a favorable profile for conditions characterized by LV diastolic dysfunction.NEW & NOTEWORTHY This is the first study to assess the direct and indirect effects of inorganic nitrite on invasive measures of left ventricular function in humans in vivo. Inorganic nitrite has a modest direct myocardial effect, improving diastolic function. Systemic administration of nitrite has larger effects related to alterations in cardiac preload and afterload. The changes induced by nitrite appear favorable for potential use in conditions characterized by LV diastolic dysfunction.

SCAI cardiogenic shock classification after out of hospital cardiac arrest and association with outcome.

OBJECTIVES: We aimed to validate the Society for Cardiovascular Angiography and Interventions (SCAI) classification to evaluate association with outcome in a real-world population and effect of invasive therapies. BACKGROUND: Cardiogenic shock is common after Out of Hospital Cardiac Arrest (OOHCA) but is often multifactorial and challenging to stratify. METHODS: The SCAI shock grade was applied to an observational registry of OOHCA patients on admission to our center between 2012 and 2017. The primary end-point was 30-day mortality and secondary end-points were mode of death and 12-month mortality. Provision of early CAG and mechanical circulatory support (MCS) was evaluated by SCAI shock grade using logistic regression. RESULTS: Three hundred and ninety-three patients (median age 64.3 years (24.9% females) were included. One hundred and seven patients (27.2%) were in Grade A, 94 (23.9%) in Grade B, 66 (16.8%) in Grade C, 91 (23.2%) in Grade D, and 35 (8.9%) in Grade E. There was a step-wise significant increase in 30-day mortality with increasing shock grade (A 28.9% vs. B 33.0% vs. C 54.5% vs. D 59.3% vs. E 82.9%; p < .0001). With worsening shock grade, requirement for renal replacement therapy and mortality from multiorgan dysfunction syndrome and cardiogenic causes increased. Early CAG was performed equally in all groups but was significantly associated with reduced mortality in SCAI grade D only (OR 0.26 [CI 0.08-0.91], p = .036). CONCLUSIONS: Increasing SCAI shock grade after OOHCA is associated with 30-day mortality, requirement for renal replacement therapy and mortality attributed to multiorgan dysfunction syndrome and cardiac etiology death.

The human coronary vasodilatory response to acute mental stress is mediated by neuronal nitric oxide synthase.

Mental stress-induced ischemia approximately doubles the risk of cardiac events in patients with coronary artery disease, yet the mechanisms underlying changes in coronary blood flow in response to mental stress are poorly characterized. Neuronal nitric oxide synthase (nNOS) regulates basal coronary blood flow in healthy humans and mediates mental stress-induced vasodilation in the forearm. However, its possible role in mental stress-induced increases in coronary blood flow is unknown. We studied 11 patients (6 men and 5 women, mean age: 58 ± 14 yr) undergoing elective diagnostic cardiac catheterization and assessed the vasodilator response to mental stress elicited by the Stroop color-word test. Intracoronary substance P (20 pmol/min) and isosorbide dinitrate (1 mg) were used to assess endothelium-dependent and -independent vasodilation, respectively. Coronary blood flow was estimated using intracoronary Doppler recordings and quantitative coronary angiography to measure coronary artery diameter. Mental stress increased coronary flow by 34 ± 7.0% over the preceding baseline during saline infusion (P < 0.01), and this was reduced to 26 ± 7.0% in the presence of the selective nNOS inhibitor S-methyl-l-thiocitrulline (0.625 µmol/min, P < 0.001). Mental stress increased coronary artery diameter by 6.9 ± 3.7% (P = 0.02) and 0.5 ± 2.8% (P = 0.51) in the presence of S-methyl-l-thiocitrulline. The response to substance P did not predict the response to mental stress (r2 = -0.22, P = 0.83). nNOS mediates the human coronary vasodilator response to mental stress, predominantly through actions at the level of coronary resistance vessels.NEW & NOTEWORTHY Acute mental stress induces vasodilation of the coronary microvasculature. Here, we show that this response involves neuronal nitric oxide synthase in the human coronary circulation.Listen to this article's corresponding podcast at http://ajpheart.podbean.com/e/nnos-and-coronary-flow-during-mental-stress/.

Pulmonary function, CT and echocardiographic abnormalities in sickle cell disease.

OBJECTIVES: To test the hypothesis that vascular abnormalities on high-resolution CT (HRCT) would be associated with echocardiographic changes and lung function abnormalities in patients with sickle cell disease (SCD) and the decline in lung function seen in SCD patients. METHODS: HRCT, echocardiography and lung function assessments were made in 35 adults, 20 of whom had previously been assessed a median of 6.6 years prior to this study. The pulmonary arterial dimensions on HRCT were quantified as the mean segmental pulmonary artery/bronchus (A/B) ratio and the summated cross-sectional area of all pulmonary vessels <5 mm in diameter (cross-sectional area (CSA)<5 mm%). RESULTS: The segmental A/B ratio was negatively correlated with FEV1, vital capacity (VC), forced expiratory flow between 25% and 75% of VC (FEF25/75) and arterial oxygen saturation (SpO2) and positively with the residual volume: total lung capacity ratio (RV:TLC) and respiratory system resistance (Rrs). CSA<5 mm% was negatively correlated with FEV1, FEF25/75 and SpO2 and positively with RV, RV:TLC and respiratory system resistance (Rrs). There were significant correlations between cardiac output assessed by echocardiography and the segmental A/B ratio and CSA<5 mm%. Lung function (FEV1 p=0.0004, VC p=0.0347, FEF25/75 p=0.0033) and the segmental A/B ratio (p=0.0347) and CSA<5 mm% (p<0.0001) significantly deteriorated over the follow-up period. CONCLUSIONS: Abnormalities in pulmonary vascular volumes may explain some of the lung function abnormalities and the decline in lung function seen in adults with SCD.

Impact of lesion morphology on stent elongation during bifurcation PCI: an in vivo OCT study.

BACKGROUND: Recent observations in silico and in vivo reported that, during proximal optimisation technique, drug-eluting stents (DES) elongate, challenging conventional wisdom. The interaction between plaque morphology and radial expansion is well established, but little is known about the impact of plaque morphology on elongation. AIMS: We aimed to assess the longitudinal mechanical behaviour of contemporary DES in vivo and evaluate the relationship between post-percutaneous coronary intervention (PCI) stent elongation and lesion morphology, as assessed with optical coherence tomography (OCT). METHODS: Patients treated with OCT-guided PCI to left main or left anterior descending artery bifurcations, between July 2017 and March 2022, from the King's Optical coherence Database Analysis Compendium were included. Patients were excluded if there were overlapping stents, if they had undergone prior PCI, or if there was inadequate image quality. Lesions were characterised as fibrocalcific, fibrous or lipid-rich by pre-PCI OCT. Following stent post-dilatation, stent expansion and final stent length were assessed. The primary outcome was the percentage change in stent length from baseline. RESULTS: Of 501 eligible consecutive patients from this period, 116 were included. The median age was 66 years (interquartile range [IQR] 57-76), 31% were female, and 53.4% were treated for an acute coronary syndrome. A total of 50.0% of lesions were classified as fibrocalcific, 6.9% were fibrous, and 43.1% were lipid-rich. The change in relative stent length was 4.4% (IQR 1.0-8.9), with an increase of 3.1% (IQR 0.5-6.3) in fibrocalcific lesions, 3.3% (IQR 0.5-5.9) in fibrous lesions, and 6.4% (IQR 3.1-11.1) in lipid-rich plaque (p=0.006). In multivariate regression modelling, lipid-rich plaque was an independent predictor of stent elongation (odds ratio 3.689, 95% confidence interval: 1.604-8.484). CONCLUSIONS: Contemporary DES elongate following implantation and post-dilatation, and this is significantly mediated by plaque morphology. This is an important consideration when planning a strategy for DES implantation.

Race- and Ethnicity-Related Differences in Heart Failure With Preserved Ejection Fraction Using Natural Language Processing.

Background: Heart failure with preserved ejection fraction (HFpEF) is the predominant form of HF in older adults. It represents a heterogenous clinical syndrome that is less well understood across different ethnicities. Objectives: This study aimed to compare the clinical presentation and assess the diagnostic performance of existing HFpEF diagnostic tools between ethnic groups. Methods: A validated Natural Language Processing (NLP) algorithm was applied to the electronic health records of a large London hospital to identify patients meeting the European Society of Cardiology criteria for a diagnosis of HFpEF. NLP extracted patient demographics (including self-reported ethnicity and socioeconomic status), comorbidities, investigation results (N-terminal pro-B-type natriuretic peptide, H2FPEF scores, and echocardiogram reports), and mortality. Analyses were stratified by ethnicity and adjusted for socioeconomic status. Results: Our cohort consisted of 1,261 (64%) White, 578 (29%) Black, and 134 (7%) Asian patients meeting the European Society of Cardiology HFpEF diagnostic criteria. Compared to White patients, Black patients were younger at diagnosis and more likely to have metabolic comorbidities (obesity, diabetes, and hypertension) but less likely to have atrial fibrillation (30% vs 13%; P < 0.001). Black patients had lower N-terminal pro-B-type natriuretic peptide levels and a lower frequency of H2FPEF scores ≥6, indicative of likely HFpEF (26% vs 44%; P < 0.0001). Conclusions: Leveraging an NLP-based artificial intelligence approach to quantify health inequities in HFpEF diagnosis, we discovered that established markers systematically underdiagnose HFpEF in Black patients, possibly due to differences in the underlying comorbidity patterns. Clinicians should be aware of these limitations and its implications for treatment and trial recruitment.

Validation of the CREST model and comparison with SCAI shock classification for the prediction of circulatory death in resuscitated out-of-hospital cardiac arrest.

AIMS: We validated the CREST model, a 5 variable score for stratifying the risk of circulatory aetiology death (CED) following out-of-hospital cardiac arrest (OHCA) and compared its discrimination with the SCAI shock classification. Circulatory aetiology death occurs in approximately a third of patients admitted after resuscitated OHCA. There is an urgent need for improved stratification of the patient with OHCA on arrival to a cardiac arrest centre to improve patient selection for invasive interventions. METHODS AND RESULTS: The CREST model and SCAI shock classification were applied to a dual-centre registry of 723 patients with cardiac aetiology OHCA, both with and without ST-elevation myocardial infarction (STEMI), between May 2012 and December 2020. The primary endpoint was a 30-day CED. Of 509 patients included (62.3 years, 75.4% male), 125 patients had CREST = 0 (24.5%), 162 had CREST = 1 (31.8%), 140 had CREST = 2 (27.5%), 75 had CREST = 3 (14.7%), 7 had a CREST of 4 (1.4%), and no patients had CREST = 5. Circulatory aetiology death was observed in 91 (17.9%) patients at 30 days [STEMI: 51/289 (17.6%); non-STEMI (NSTEMI): 40/220 (18.2%)]. For the total population, and both NSTEMI and STEMI subpopulations, an increasing CREST score was associated with increasing CED (all P < 0.001). The CREST score and SCAI classification had similar discrimination for the total population [area under the receiver operating curve (AUC) = 0.72/calibration slope = 0.95], NSTEMI cohort (AUC = 0.75/calibration slope = 0.940), and STEMI cohort (AUC = 0.69 and calibration slope = 0.925). Area under the receiver operating curve meta-analyses demonstrated no significant differences between the two classifications. CONCLUSION: The CREST model and SCAI shock classification show similar prediction results for the development of CED after OHCA.

Artificial intelligence methods for improved detection of undiagnosed heart failure with preserved ejection fraction.

AIM: Heart failure with preserved ejection fraction (HFpEF) remains under-diagnosed in clinical practice despite accounting for nearly half of all heart failure (HF) cases. Accurate and timely diagnosis of HFpEF is crucial for proper patient management and treatment. In this study, we explored the potential of natural language processing (NLP) to improve the detection and diagnosis of HFpEF according to the European Society of Cardiology (ESC) diagnostic criteria. METHODS AND RESULTS: In a retrospective cohort study, we used an NLP pipeline applied to the electronic health record (EHR) to identify patients with a clinical diagnosis of HF between 2010 and 2022. We collected demographic, clinical, echocardiographic and outcome data from the EHR. Patients were categorized according to the left ventricular ejection fraction (LVEF). Those with LVEF ≥50% were further categorized based on whether they had a clinician-assigned diagnosis of HFpEF and if not, whether they met the ESC diagnostic criteria. Results were validated in a second, independent centre. We identified 8606 patients with HF. Of 3727 consecutive patients with HF and LVEF ≥50% on echocardiogram, only 8.3% had a clinician-assigned diagnosis of HFpEF, while 75.4% met ESC criteria but did not have a formal diagnosis of HFpEF. Patients with confirmed HFpEF were hospitalized more frequently; however the ESC criteria group had a higher 5-year mortality, despite being less comorbid and experiencing fewer acute cardiovascular events. CONCLUSIONS: This study demonstrates that patients with undiagnosed HFpEF are an at-risk group with high mortality. It is possible to use NLP methods to identify likely HFpEF patients from EHR data who would likely then benefit from expert clinical review and complement the use of diagnostic algorithms.

Prognostic significance of troponin in patients with malignancy (NIHR Health Informatics Collaborative TROP-MALIGNANCY study).

BACKGROUND: Cardiac troponin is commonly raised in patients presenting with malignancy. The prognostic significance of raised troponin in these patients is unclear. OBJECTIVES: We sought to investigate the relation between troponin and mortality in a large, well characterised cohort of patients with a routinely measured troponin and a primary diagnosis of malignancy. METHODS: We used the National Institute for Health Research (NIHR) Health Informatics Collaborative data of 5571 patients, who had troponin levels measured at 5 UK cardiac centres between 2010 and 2017 and had a primary diagnosis of malignancy. Patients were classified into solid tumour or haematological malignancy subgroups. Peak troponin levels were standardised as a multiple of each laboratory's 99th -percentile upper limit of normal (xULN). RESULTS: 4649 patients were diagnosed with solid tumours and 922 patients with haematological malignancies. Raised troponin was an independent predictor of mortality in all patients (Troponin > 10 vs. <1 adjusted HR 2.01, 95% CI 1.73 to 2.34), in solid tumours (HR 1.84, 95% CI 1.55 to 2.19), and in haematological malignancy (HR 2.72, 95% CI 1.99 to 3.72). There was a significant trend in increasing mortality risk across troponin categories in all three subgroups (p < 0.001). CONCLUSION: Raised troponin level is associated with increased mortality in patients with a primary diagnosis of malignancy regardless of cancer subtype. Mortality risk is stable for patients with a troponin level below the ULN but increases as troponin level increases above the ULN in the absence of acute coronary syndrome.

Sympathetic activation increases NO release from eNOS but neither eNOS nor nNOS play an essential role in exercise hyperemia in the human forearm.

Nitric oxide (NO) release from endothelial NO synthase (eNOS) and/or neuronal NO synthase (nNOS) could be modulated by sympathetic nerve activity and contribute to increased blood flow after exercise. We examined the effects of brachial-arterial infusion of the nNOS selective inhibitor S-methyl-l-thiocitrulline (SMTC) and the nonselective NOS inhibitor N(G)-monomethyl-l-arginine (l-NMMA) on forearm arm blood flow at rest, during sympathetic activation by lower body negative pressure, and during lower body negative pressure immediately after handgrip exercise. Reduction in forearm blood flow by lower body negative pressure during infusion of SMTC was not significantly different from that during vehicle (-28.5 ± 4.02 vs. -34.1 ± 2.96%, respectively; P = 0.32; n = 8). However, l-NMMA augmented the reduction in forearm blood flow by lower body negative pressure (-44.2 ± 3.53 vs. -23.4 ± 5.71%; n = 8; P < 0.01). When lower body negative pressure was continued after handgrip exercise, there was no significant effect of either l-NMMA or SMTC on forearm blood flow immediately after low-intensity exercise (P = 0.91 and P = 0.44 for l-NMMA vs. saline and SMTC vs. saline, respectively; each n = 10) or high-intensity exercise (P = 0.46 and P = 0.68 for l-NMMA vs. saline and SMTC vs. saline, respectively; each n = 10). These results suggest that sympathetic activation increases NO release from eNOS, attenuating vasoconstriction. Dysfunction of eNOS could augment vasoconstrictor and blood pressure responses to sympathetic activation. However, neither eNOS nor nNOS plays an essential role in postexercise hyperaemia, even in the presence of increased sympathetic activation.

Differential role of endothelial versus neuronal nitric oxide synthase in the regulation of coronary blood flow during pacing-induced increases in cardiac workload.

Endothelial nitric oxide synthase (eNOS) was assumed to be the only source of nitric oxide (NO) involved in the regulation of human coronary blood flow (CBF). However, our recent first-in-human study using the neuronal NOS (nNOS)-selective inhibitor S-methyl-L-thiocitrulline (SMTC) showed that nNOS-derived NO also plays a role. In this study, we investigated the relative contribution of nNOS and eNOS to the CBF response to a pacing-induced increase in cardiac workload. Incremental right atrial pacing was undertaken in patients with angiographically normal coronary arteries during intracoronary infusion of saline vehicle and then either SMTC or N(G)-monomethyl-l-arginine (l-NMMA; which inhibits both eNOS and nNOS). Intracoronary SMTC (0.625 µmol/min) and l-NMMA (25 µmol/min) reduced basal CBF to a similar extent (-19.2 ± 3.2% and 25.0 ± 2.7%, respectively; n = 10 per group). Pacing-induced increases in CBF were significantly blunted by l-NMMA (maximum CBF: 83.5 ± 14.2 ml/min during saline vs. 61.6 ± 9.5 ml/min during l-NMMA; P < 0.01). By contrast, intracoronary SMTC had no effect on the maximum CBF during pacing (98.5 ± 12.9 ml/min during saline vs. 102.1 ± 16.6 ml/min during SMTC; P = not significant). l-NMMA also blunted the pacing-induced increase in coronary artery diameter (P < 0.001 vs. saline), whereas SMTC had no effect. Our results confirm a role of nNOS in the regulation of basal CBF in humans but show that coronary vasodilation in response to a pacing-induced increase in cardiac workload is exclusively mediated by eNOS-derived NO.

Coronary Artery Disease in Patients with Severe Mental Illness.

Severe mental illnesses (SMI), such as schizophrenia and bipolar disorder, are associated with a decrease in life expectancy of up to two decades compared with the general population, with cardiovascular disease as the leading cause of death. SMI is associated with increased cardiovascular risk profile and early onset of incident cardiovascular disease. Following an acute coronary syndrome, patients with SMI have a worse prognosis, but are less likely to receive invasive treatment. In this narrative review, the management of coronary artery disease in patients with SMI is discussed, and avenues for future research are highlighted.

The effect of ethnicity and socioeconomic status on outcomes after resuscitated out-of-hospital cardiac arrest - Findings from a tertiary centre in South London.

Background: Out-of-hospital cardiac arrest is a common cause of morbidity and mortality, and ethnic variation in outcomes is recognised. We investigated ethnic and socioeconomic differences in arrest circumstances, rates of coronary artery disease, treatment, and outcomes in resuscitated OOHCA. Methods: Patients with resuscitated OOHCA of suspected cardiac aetiology were included in the King's Out-of-Hospital Cardiac Arrest Registry between 1-May-2012 and 31-December-2020. Results: Of 526 patients (median age 62.0 years, IQR 21.1, 74.1% male), 414 patients (78.7%) were White, 35 (6.7%) were Asian, and 77 (14.6%) were Black. Black patients had more co-existent hypertension (p = 0.007) and cardiomyopathy (p = 0.003), but less prior coronary revascularisation (p = 0.026) compared with White/Asian patients. There were no ethnic differences in location, witnesses, or bystander CPR, but Black patients had more non-shockable rhythms (p < 0.001). Black patients received less immediate coronary angiography (p < 0.001) and percutaneous coronary intervention (p < 0.001) but had lower rates of CAD (p = 0.004) than White/Asian patients. All-cause mortality at 12 months was highest amongst Black patients, followed by Asian and then White patients (57.1% vs 48.6% vs 41.3%, p = 0.032). In Black patients, excess mortality was driven by higher rates of multi-organ dysfunction but lower cardiac death than White/Asian patients, with cardiac death highest amongst Asian patients (p = 0.009). Socioeconomic status had no effect on mortality, and in a multivariable logistic regression, age, location, witnesses, and Black compared to White ethnicity were independent predictors of mortality, whilst social deprivation was not. Conclusion: In this single-centre study, Black patients had higher mortality after resuscitated OOHCA than White/Asian patients. This may be in part due to differing underlying aetiology rather than differences in arrest circumstances or social deprivation.

MIRACLE2 Score Compared With Downtime and Current Selection Criterion for Invasive Cardiovascular Therapies After OHCA.

BACKGROUND: The MIRACLE2 score is the only risk score that does not incorporate and can be used for selection of therapies after out-of-hospital cardiac arrest (OHCA). OBJECTIVES: This study sought to compare the discrimination performance of the MIRACLE2 score, downtime, and current randomized controlled trial (RCT) recruitment criteria in predicting poor neurologic outcome after out-of-hospital cardiac arrest (OHCA). METHODS: We used the EUCAR (European Cardiac Arrest Registry), a retrospective cohort from 6 centers (May 2012-September 2022). The primary outcome was poor neurologic outcome on hospital discharge (cerebral performance category 3-5). RESULTS: A total of 1,259 patients (total downtime = 25 minutes; IQR: 15-36 minutes) were included in the study. Poor outcome occurred in 41.8% with downtime <30 minutes and in 79.3% for those with downtime >30 minutes. In a multivariable logistic regression analysis, MIRACLE2 had a stronger association with outcome (OR: 2.23; 95% CI: 1.98-2.51; P < 0.0001) than zero flow (OR: 1.07; 95% CI: 1.01-1.13; P = 0.013), low flow (OR: 1.04; 95% CI: 0.99-1.09; P = 0.054), and total downtime (OR: 0.99; 95% CI: 0.95-1.03; P = 0.52). MIRACLE2 had substantially superior discrimination for the primary endpoint (AUC: 0.877; 95% CI: 0.854-0.897) than zero flow (AUC: 0.610; 95% CI: 0.577-0.642), low flow (AUC: 0.725; 95% CI: 0.695-0.754), and total downtime (AUC: 0.732; 95% CI: 0.701-0.760). For those modeled for exclusion from study recruitment, the positive predictive value of MIRACLE2 ≥5 for poor outcome was significantly higher (0.92) than the CULPRIT-SHOCK (Culprit lesion only PCI Versus Multivessel PCI in Cardiogenic Shock) (0.80), EUROSHOCK (Testing the value of Novel Strategy and Its Cost Efficacy In Order to Improve the Poor Outcomes in Cardiogenic Shock) (0.74) and ECLS-SHOCK (Extra-corporeal life support in Cardiogenic shock) criteria (0.81) (P < 0.001). CONCLUSIONS: The MIRACLE2 score has superior prediction of outcome after OHCA than downtime and higher discrimination of poor outcome than the current RCT recruitment criteria. The potential for the MIRACLE2 score to improve the selection of OHCA patients should be evaluated formally in future RCTs.

Renal impairment is associated with coronary heart disease in HIV-positive men.

BACKGROUND: Chronic kidney disease is a risk factor for coronary heart disease (CHD). The association between renal impairment and CHD in HIV-positive patients remains poorly described. OBJECTIVE: To describe the CHD incidence in a cohort of HIV-positive patients and to examine the relationship between reduced estimated glomerular filtration rate (eGFR) and incident CHD. METHODS: We studied 7,828 HIV-positive patients who were followed up at 3 South London clinics between January 2004 and December 2009. CHD events were identified from electronic records and through elevated troponin levels. Multivariate Poisson regression analysis was used to identify factors associated with CHD among HIV-positive men. RESULTS: The incidence of CHD among men was 1.2 (95% CI, 0.8-1.8) per 1,000 person-years of follow-up, with 28 patients (0.4%) having experienced 32 CHD events. In adjusted analyses, older age (incidence rate ratios [IRR], 2.81; 95% CI, 1.51-5.25) and hepatitis C virus (HCV) status (IRR, 3.94; 95% CI, 1.00-15.5) were significantly associated with CHD. Although eGFR as a continuous variable was not associated with CHD, an eGFR <75 mL/min remained associated with incident CHD (IRR, 4.30; 95% CI, 1.33-14.5) after adjustment for age. No association between CHD and abacavir exposure was observed (IRR, 0.94; 95% CI, 0.30-2.99). CONCLUSIONS: The incidence of CHD in this ethnically diverse cohort was low. Our data suggest that impaired renal function identifies patients at increased risk of CHD events in whom management of traditional CHD risk factors should be prioritized.

Clinical Significance of Early Echocardiographic Changes after Resuscitated Out-of-Hospital Cardiac Arrest.

BACKGROUND: Left Ventricular Systolic Dysfunction (LVSD) is common after out-of-hospital cardiac arrest (OOHCA) and can manifest globally or regionally, although its clinical significance has not been robustly studied. This study evaluates the association between LVSD, extent of coronary artery disease (CAD) and outcome in those undergoing early echocardiography and coronary angiography after OOHCA. METHODS: Trans-thoracic echocardiography (TTE) was performed in OOHCA patients on arrival to our centre between May 2012 and December 2017. Rates of cardiogenic shock and extent of CAD, respectively classified by SCAI grade and the SYNTAX score, were measured. The primary end-point was 12-month mortality. RESULTS: From 398 patients in the King's Out of Hospital Cardiac Arrest Registry (KOCAR), 266 patients (median age 61 [53-71], 76% male) underwent both TTE and coronary angiography on arrival. 96 patients (36%) had significant LVSD (Left Ventricular Ejection Fraction [LVEF] <40%) and 139 (52.2%) patients had regional wall motion abnormalities (RWMAs). Patients with LVEF <40% had more SCAI grade C-E shock (65.3% vs. 34.5%, p <0.001) and higher 12-month mortality (55.2% vs 31.8%, p <0.001) which was more likely to be due to a cardiac aetiology (27.3% vs 5.3%, p <0.001). Patients with RWMAs had higher median SYNTAX scores (14.75 vs 7, p=0.001), culprit coronary lesions (83.5% vs. 45.3%, p <0.001) and lower 12-month mortality (29.5% vs 52%, p <0.001). CONCLUSIONS: Patients with LVEF <40% at presentation have an increased mortality, driven by cardiac aetiology death, while the presence of RWMAs is associated with a higher rate of culprit coronary lesions, representing a potentially reversible cause of the arrest, and improved survival at 1 year.

Coronary Wave Intensity Analysis as an Invasive and Vessel-Specific Index of Myocardial Viability.

BACKGROUND: Coronary angiography and viability testing are the cornerstones of diagnosing and managing ischemic cardiomyopathy. At present, no single test serves both needs. Coronary wave intensity analysis interrogates both contractility and microvascular physiology of the subtended myocardium and therefore has the potential to fulfil the goal of completely assessing coronary physiology and myocardial viability in a single procedure. We hypothesized that coronary wave intensity analysis measured during coronary angiography would predict viability with a similar accuracy to late-gadolinium-enhanced cardiac magnetic resonance imaging. METHODS: Patients with a left ventricular ejection fraction ≤40% and extensive coronary disease were enrolled. Coronary wave intensity analysis was assessed during cardiac catheterization at rest, during adenosine-induced hyperemia, and during low-dose dobutamine stress using a dual pressure-Doppler sensing coronary guidewire. Scar burden was assessed with cardiac magnetic resonance imaging. Regional left ventricular function was assessed at baseline and 6-month follow-up after optimization of medical-therapy±revascularization, using transthoracic echocardiography. The primary outcome was myocardial viability, determined by the retrospective observation of functional recovery. RESULTS: Forty participants underwent baseline physiology, cardiac magnetic resonance imaging, and echocardiography, and 30 had echocardiography at 6 months; 21/42 territories were viable on follow-up echocardiography. Resting backward compression wave energy was significantly greater in viable than in nonviable territories (-5240±3772 versus -1873±1605 W m-2 s-1, P<0.001), and had comparable accuracy to cardiac magnetic resonance imaging for predicting viability (area under the curve 0.812 versus 0.757, P=0.649); a threshold of -2500 W m-2 s-1 had 86% sensitivity and 76% specificity. CONCLUSIONS: Backward compression wave energy has accuracy similar to that of late-gadolinium-enhanced cardiac magnetic resonance imaging in the prediction of viability. Coronary wave intensity analysis has the potential to streamline the management of ischemic cardiomyopathy, in a manner analogous to the effect of fractional flow reserve on the management of stable angina.