Plasma endothelin-1 and adrenomedullin are associated with coronary artery function and cardiovascular outcomes in humans

BACKGROUND

Endothelin-1 (ET-1) is a vasoconstrictor associated with cardiovascular disease, whereas adrenomedullin (ADM) is a vasorelaxant with cardioprotective properties. We sought to determine the relationship between plasma ET-1 and ADM with coronary circulatory function and long-term major adverse cardiovascular events (MACE).

METHODS

Thirty-two patients undergoing coronary angiography for chest pain were recruited. Baseline plasma ET-1 and ADM levels were measured. The index of microcirculatory resistance (IMR), coronary flow mediated dilatation (cFMD) and coronary flow reserve (CFR) were measured in a non-obstructed coronary artery. Patients were assessed for MACE over a median period of 8.8 years.

RESULTS

Plasma ET-1 levels correlated with IMR (r = 0.57; p < 0.01) and ADM levels correlated with CFR (r = 0.50; p = 0.04) and cFMD (r = 0.62; p = 0.01). After adjustment for age, gender and cardiovascular risk factors, the association between ADM and cFMD (β = 0.79; p < 0.01) and between ET-1 and IMR (β = 5.7; p = 0.01) remained significant. IMR was higher, although not statistically significant, in patients with long-term MACE (17.9 ± 5.3 vs. 13.1 ± 6.0 units; p = 0.14). In patients free of MACE, cFMD (9.3 ± 7.6 vs. 2.8 ± 5.0%; p = 0.01) and plasma ADM levels (7.6 ± 5.3 vs. 4.0 ± 1.9 pmol/L; p = 0.07) were higher.

CONCLUSIONS

Plasma ET-1 and ADM were associated with measures of coronary microvascular and coronary conduit vessel function, respectively. Increased cFMD and elevated plasma ADM were associated with a cardioprotective effect.

Acute Coronary Syndrome in the COVID-19 Pandemic: Reduced Cases and Increased Ischaemic Time

BACKGROUND

The COVID-19 pandemic has led to unprecedented stress on health care systems, and has affected acute coronary syndrome treatment at every step. This study aimed to examine the impact of COVID-19 on patient presentations with acute coronary syndromes during the first and second pandemic wave in Melbourne, Victoria.

METHOD

A retrospective cohort study of adults presenting with cute coronary syndrome during the first pandemic wave from 1 March 2020 to 31 April 2020 and the second pandemic wave from 1 July 2020 to 31 August 2020 was compared to a control period from 1 March to 31 April 2019 at a single sub-tertiary referral centre in Melbourne, Victoria servicing a catchment area with a relatively high incidence of COVID-19 cases.

RESULTS

Three-hundred-and-thirty-five (335) patients were hospitalised with acute coronary syndromes across all three time periods. The total number of patients presenting with an acute coronary syndrome was reduced during the pandemic, with a higher proportion of ST elevation myocardial infarctions. Ischaemic times increased with time from symptom onset to first medical contact rising from 191 minutes in the control period to 292 minutes in the first wave (p=0.06) and 271 minutes in the second wave (p=0.06). Coronary angiography with subsequent revascularisation significantly increased from 55% in the control period undergoing revascularisation to 69% in the first wave (p<0.001) and 74% in the second wave (p<0.001).

CONCLUSION

A concerning reduction in acute coronary presentations occurred during the COVID-19 pandemic, associated with longer ischaemic times and a higher proportion requiring revascularisation. It is crucial that public awareness campaigns are instituted to address the contributing patient factors in future waves.

Impact of insulin initiation on glycaemic variability and glucose profiles in a primary healthcare Type 2 diabetes cohort: analysis of continuous glucose monitoring data from the INITIATION study

AIM

To use continuous glucose monitoring to examine the effects of insulin initiation with glargine, with or without glulisine, on glycaemic variability and glycaemia in a cohort of people with Type 2 diabetes receiving maximum oral hypoglycaemic agents in primary healthcare.

METHODS

We conducted a post hoc analysis of continuous glucose monitoring data from 89 participants at baseline and at 24 weeks after insulin commencement. Indicators of glycaemic variability (standard deviation, J-index and mean amplitude of glycaemic excursion) and glycaemia (HbA1c , mean glucose, area under the glucose-time curve) were assessed. Multi-level regression analysis was used to identify the predictors of change.

RESULTS

Complete glycaemic variability data were available for 78 participants. Of these participants, 41% were women, their mean (sd) age was 59.2 (10.4) years, the median (interquartile range) diabetes duration was 10.4 (6.5, 13.3) years and the median (interquartile range) baseline HbA1c was 82.5 (71.6, 96.7) mmol/mol [9.7 (8.7, 11.0)%]. At baseline, BMI correlated negatively with standard deviation (r = -0.30) and mean amplitude of glycaemic excursion (r = -0.26), but not with J-index; HbA1c correlated with J-index (r = 0.61) but not with mean amplitude of glycaemic excursion and standard deviation. After insulin initiation the mean (sd) glucose level decreased [from 12.0 (3.0) to 8.5 (1.6) mmol/l; P < 0.001], as did the median (interquartile range) J-index [from 66.9 (47.7, 95.1) to 36.9 (27.6, 49.8) mmol/l; P < 0.001]. Baseline HbA1c correlated with a greater J-index reduction (r = -0.45; P < 0.001). The mean amplitude of glycaemic excursion and standard deviation values were unchanged. The baseline temporal profile, showing elevated postprandial morning glucose levels, was unchanged after insulin initiation, despite an overall reduction in glycaemia.

CONCLUSION

Insulin initiation reduced hyperglycaemia but did not alter glycaemic variability in adults with Type 2 diabetes receiving maximum oral hypoglycaemic agents. The most significant postprandial excursions were seen in the morning, which identifies prebreakfast as the most effective target for short-acting insulin therapy.

Feasibility of exercise stress echocardiography for cardiac risk assessment in chronic kidney disease patients prior to renal transplantation

BACKGROUND

Pharmacologic stress testing is utilized in preference to exercise stress echocardiography (ESE) for cardiac risk evaluation in potential renal transplant recipients due to the perceived lower feasibility of ESE for achieving adequate workload and target heart rate (THR) in this population.

METHODS

Consecutive patients referred for cardiac risk evaluation prior to potential kidney transplantation were evaluated. All patients attempted ESE before pharmacologic testing was considered. Treadmill ESE utilized BRUCE protocol to maximum capacity. THR was defined as >85% of the maximum predicted heart rate (220-age). Functional capacity was assessed by metabolic equivalents (METs) and the rate pressure product (RPP).

RESULTS

Of 535 patients (349 male, age 56±11), 372(70%) reached THR. Mean METs were 10±3 with 531(99%) achieving ≥4 METs and 87% ≥7 METs. Mean RPP was 25 821±5820 bpm×mm Hg (83% achieving >20 000 bpm×mm Hg). On multivariate analysis, independent predictors of failure to reach THR were rate-control medication and diabetes; failure to reach 7 METs: females, diabetics, age≥65, and previous cardiac disease; failure to reach RPP>20 000: rate-control medication. There were 97% of ESE completed to physiologic endpoints.

CONCLUSION

In unselected potential renal transplant candidates, cardiac assessment by ESE is well tolerated, with 9-in-10 exercising to satisfactory functional capacity. ESE should be considered a feasible alternative to pharmacologic testing in this population.

Permanent pacing and conduction recovery in patients undergoing cardiac surgery for active infective endocarditis in an Australian Tertiary Center

BACKGROUND

Postoperative heart block is common among patients undergoing surgery for infective endocarditis (IE). Limited data exists allowing cardiologists to predict who will require permanent pacemaker (PPM) implantation postoperatively. We aimed to determine the rate of postoperative PPM insertion, predictors for postoperative PPM, and describe PPM utilization and rates of device-related infection during follow-up.

MATERIALS AND METHODS

A retrospective analysis was performed of 191 consecutive patients from a single institution who underwent cardiac surgery for IE between 2001 and 2017. Preoperative and operative predictors for postoperative PPM were evaluated using univariate and multivariate logistic regression.

RESULTS

The rate of postoperative PPM implantation was 11% (17/154). The PPM group had more preoperative prolonged PR interval alone (33% vs 12%; P = .03), coexistent prolonged PR and QRS durations (13% vs 2%; P = .01), infection beyond the valve leaflets (82% vs 41%; P = .001), aortic root debridement (65% vs 23%; P = <.001), patch repair (47% vs 20%; P = .01), postoperative prolonged PR interval (50% vs 24%; P = .01), and prolonged QRS duration (47% vs 15%; P = .001). On multivariate analysis, infection beyond the valve leaflets emerged as an independent predictor for postoperative PPM (odds ratio, 1.94, 95% confidence interval, 1.14-3.28; P = .014). A reduction in PPM utilization was observed in five patients while eight patients continued to show significant ventricular pacing with no underlying rhythm at 12 months. There were no device-related infections.

CONCLUSION

Postoperative PPM was required in 11% of patients undergoing surgery for IE over a 16-year period. Infection beyond the valve leaflet was an independent predictor for postoperative PPM insertion.

Association of hypertension with mortality in patients hospitalised with COVID-19

Objective

To assess whether hypertension is an independent risk factor for mortality among patients hospitalised with COVID-19, and to evaluate the impact of ACE inhibitor and angiotensin receptor blocker (ARB) use on mortality in patients with a background of hypertension.

Method

This observational cohort study included all index hospitalisations with laboratory-proven COVID-19 aged ≥18 years across 21 Australian hospitals. Patients with suspected, but not laboratory-proven COVID-19, were excluded. Registry data were analysed for in-hospital mortality in patients with comorbidities including hypertension, and baseline treatment with ACE inhibitors or ARBs.

Results

546 consecutive patients (62.9±19.8 years old, 51.8% male) hospitalised with COVID-19 were enrolled. In the multivariable model, significant predictors of mortality were age (adjusted OR (aOR) 1.09, 95% CI 1.07 to 1.12, p<0.001), heart failure or cardiomyopathy (aOR 2.71, 95% CI 1.13 to 6.53, p=0.026), chronic kidney disease (aOR 2.33, 95% CI 1.02 to 5.32, p=0.044) and chronic obstructive pulmonary disease (aOR 2.27, 95% CI 1.06 to 4.85, p=0.035). Hypertension was the most prevalent comorbidity (49.5%) but was not independently associated with increased mortality (aOR 0.92, 95% CI 0.48 to 1.77, p=0.81). Among patients with hypertension, ACE inhibitor (aOR 1.37, 95% CI 0.61 to 3.08, p=0.61) and ARB (aOR 0.64, 95% CI 0.27 to 1.49, p=0.30) use was not associated with mortality.

Conclusions

In patients hospitalised with COVID-19, pre-existing hypertension was the most prevalent comorbidity but was not independently associated with mortality. Similarly, the baseline use of ACE inhibitors or ARBs had no independent association with in-hospital mortality.

Computed Tomography Coronary Angiography Is Feasible and Reliable for Proximal Coronary Segment Interpretation in Patients with Elevated Body Mass Index

Computed tomography coronary angiography (CTCA) is under-utilised in detecting coronary artery disease (CAD) in obese patients due to concerns about non-evaluable testing. We hypothesise that these concerns are predominantly related to smaller and branch coronary vessels, and CTCA remains adequate for proximal segment stenosis interpretation, which has significant clinical implications. This retrospective cohort study, on consecutive patients referred for CTCA for suspected CAD, grouped patients by body mass index. A 4-point Likert scale assessed image quality, with any poorly visualised segment at the per-patient level resulting in the CTCA being subsequently analysed for proximal coronary artery segment evaluability. Of the 703 patients, 93.5% of the studies were fully evaluable. Patients with a BMI ≥ 40, diabetic patients, and patients with an elevated acquisition heart rate were associated with suboptimal studies. Of the 46 suboptimal studies, 163/182 (90%) of proximal segments were fully evaluable. Non-evaluable segments were derived from seven patients (one with a BMI ≥ 40). Reasons for proximal segment non-evaluability were predominantly due to calcific blooming (12/19 segments). While CTCA may be less reliable for distal and side-branch artery evaluation in obese patients, it remains highly evaluable for stenosis severity of the proximal main coronary segments, which carries prognostic significance. It may therefore be considered a suitable non-invasive anatomic test for patients, regardless of BMI.

In vitro and in vivo evaluation of locust bean gum and chitosan combination as a carrier for buccal drug delivery

The object of the study was to evaluate locust bean gum and chitosan in ratios of 2:3; 3:2 and 4:1 (F1, F2 and F3) as a mucoadhesive component in buccal tablets and to compare the bioavailability of a propranolol hydrochloride buccal tablet with the oral tablet in healthy human volunteers. Propranolol hydrochloride buccal tablets containing various weight ratios of locust bean gum and chitosan were prepared and coated with 5% w/v ethyl cellulose on one face, and oral tablets containing 10 mg propranolol hydrochloride alone were formulated using a direct compression technique. The strength of mucoadhesion of the tablets was quantified based on the tensile force required to break the adhesive bond between a model membrane (porcine buccal mucosa) and the test polymer. The forces of detachment for the mucoadhesive buccal tablets were 14.61 +/- 0.14, 13.21 +/- 0.13 and 11.71 +/- 0.12. An in vitro study was carried out in pH 6.8 phosphate buffer and the cumulative percentage release of propranolol measured at 10 min intervals for 600 min was found to be 98.31 +/- 0.10, 92.24 +/- 0.41 and 90.18 +/- 0.76 respectively. A bioavailability study was conducted with the prepared formulation in 16 healthy human volunteers to determine the plasma concentration of propranolol at 0, 1, 2, 3, 4, 6, 8, 10 and 12 h. The bioavailability (AUC(0-t*) ng x h/ml) of the buccal propranolol hydrochloride tablets (F1, F2 and F3) and oral tablet (F4) was found to be 2244.18 +/- 210, 3580.69 +/- 460, 3889.19 +/- 290 and 1732 +/- 96 ng x hr/ml respectively. The study indicates that locust bean gum and chitosan in a weight ratio of 2:3 (F1) not only releases the drug unidirectionally from the dosage form, but also gives buccal tablets which are sufficiently mucoadhesive for clinical applications.

Ivabradine in the Prevention, and Reduction in Size, of Perioperative Myocardial Injury in Patients Undergoing Orthopedic Surgery for Acute Fracture

BACKGROUND

Perioperative myocardial injury is common after major noncardiac surgery and is associated with adverse outcomes. This study investigated the use of ivabradine in patients undergoing urgent surgery for fracture.

METHODS AND RESULTS

This was a prospective, double-blind, placebo-controlled, randomized clinical trial. Participants were enrolled 1:1 into ivabradine or placebo arm, and study drug was commenced before operation and continued for 7 days or until discharge. High-sensitivity troponin I was measured daily using Abbott Alinity analyzer and assay, and heart rate data were obtained using continuous Holter monitoring. A total of 199 patients underwent acute orthopedic surgery, 98 in the ivabradine group and 101 in the placebo group. The mean age was 78.7 years (range, 77.5-79.9 years), with 68% women. The average heart rate was 5 to 11 beats per minute lower in the ivabradine group compared with the placebo group at all time points (P<0.001 for all). There was no statistically significant difference between the ivabradine and placebo groups in the number of patients who had perioperative myocardial injury: 28.6% versus 31.6% (P=0.71). In patients with perioperative myocardial injury, average peak troponin was 168.8 ng/L (±431.2 ng/L) in the ivabradine group and 2094.5 ng/L (±7201.9 ng/L) in the placebo group (P=0.16). There was no statistically significant difference between groups in 30-day mortality, blood pressure, stroke, or major adverse cardiovascular event.

CONCLUSIONS

Starting ivabradine preoperatively in elderly patients requiring acute surgery for fracture did not result in a statistically significant difference in the incidence of perioperative myocardial injury. There was no statistically significant difference in morbidity, mortality, or adverse events between treatment groups.

REGISTRATION

URL: https://www.anzctr.org.au/; Unique identifier: ACTRN12616001634460p.

Low breast density is associated with epicardial adipose tissue volume and coronary artery disease

PURPOSE

Epicardial adipose tissue volume (EATv), is well correlated with coronary artery disease (CAD), however not reported clinically. Breast density, measured on mammography, has shown promise as a reflector of cardiometabolic risk, with less dense breasts indicating greater proportion of adipose tissue. We aimed to evaluate the association between breast density, EATv and CAD.

METHOD

Retrospective, cross-sectional study including 153 women who had both clinically indicated coronary computed tomography angiogram (CCTA) and mammography. EATv was quantified using semi-automated software. Breast density was visually assessed by standard 4-level BI-RADS grading (low: BI-RADS A-B, high: BI-RADS CD). CAD was categorised as presence/absence of coronary artery plaque and severity was quantified using CAD-RADS score.

RESULTS

Among 153 patients (mean age 62 ± 10), 103 (67.3 %) had low breast density (high breast adiposity). Low breast density patients were older, had greater rates of hypertension, higher mean BMI (p < 0.001) and EATv (106.6 ± 43.0 ml vs 81.0 ± 31.6 ml, p < 0.001). EATv was predictive of low breast density (OR: 1.02[1.01-1.03], p = 0.006), independent of age and hypertension. Low breast density was strongly associated with presence of CAD (prevalence 75 % vs 48 %, OR: 3.21[1.58-6.53], p = 0.001) independent of EATv, and modifiable (OR: 2.69[1.24-5.92], p = 0.012) and non-modifiable (OR: 2.42[1.04-5.85], p = 0.047) cardiovascular risk factors. Low breast density made up a higher proportion of mild (76.5 %), moderate (73.9 %) and severe (80.0 %) CAD.

CONCLUSIONS

Low breast density is associated with higher EATv and independently associated with CAD presence beyond EATv and other cardiovascular risk factors. Mammographic breast density may therefore have value as an early risk identification tool for CAD in women.

Combined Mammographic Breast Density and Breast Arterial Calcification as an Incremental Predictor of Coronary Artery Disease

Background: Contemporary risk calculators underestimate coronary artery disease (CAD) risk in women. Breast arterial calcification (BAC) associates with CAD. Low breast density (BD) (greater breast adipose tissue) associates with cardiometabolic disease. Both are readily identifiable on screening mammography. We sought to evaluate the association between the combined features of BD, BAC, and CAD. Methods: We retrospectively studied women with clinically indicated mammography and contemporaneous coronary computed tomography angiography. CAD risk was estimated by CAD Consortium Scoring (CCS;>15% high risk). BD was visually assessed by four-level Breast Imaging-Reporting and Data System (BI-RADS) (low:BI-RADS A-B, high:BI-RADS C-D). BAC was visually assessed as present/absent. CAD was categorized as presence/absence of coronary artery plaque. Results are presented with odds ratio (OR) and [95% confidence intervals], and area under the curve (AUC). Results: In 153 patients (age 62 ± 10), low BD (67%) and BAC presence (24%) were both associated with CAD, respectively: OR: 3.21 [1.58-6.60], p = 0.001, and OR: 4.36 [1.58-12.00], p = 0.004. CAD proportion in low BD (68.9%) and BAC (42.9%) was lower than with combined low BD+BAC positive (89.7%). Compared with (high BD+BAC negative), the presence of (low BD+BAC positive) associated with CAD independent of modifiable (OR: 9.12 [2.44-45.83], p = 0.002) and nonmodifiable (OR: 4.87 [1.22-25.02], p = 0.035) risk factors. CCS >15% was seen in 33%. Significant incremental value was seen with the addition of BD/BAC status to CCS (AUC 0.64 versus 0.73, p = 0.004). Conclusions: Mammographic BAC and low BD, both alone and combined, associate with CAD, and improve risk prediction beyond standard coronary risk estimation. Standardized reporting of these features may provide benefit and should be tested in prospective screening studies.

Effects of Combining Coronary Calcium Score With Treatment on Plaque Progression in Familial Coronary Artery Disease: A Randomized Clinical Trial

Importance

Coronary artery calcium (CAC) scoring provides prognostic information, especially in patients at intermediate risk for coronary artery disease (CAD). However, the benefit of combining CAC score with a primary prevention strategy has not been tested in a randomized trial.

Objective

To assess whether combining the CAC score with a prevention strategy can be used to limit plaque progression in intermediate-risk patients with a family history of premature CAD.

Design, Setting, and Participants

Prospective, randomized, open-blinded end point clinical trial in 7 hospitals across Australia (between 2013 and 2020; the last date of follow-up was June 5, 2021). Asymptomatic people aged 40 to 70 years with a first-degree relative with CAD onset at younger than 60 years old or second-degree relative with onset at younger than 50 years old were recruited from the community.

Interventions

Intermediate-risk participants underwent CAC scoring. Those with a CAC score greater than 0 but less than 400 underwent coronary computed tomography angiography (CCTA) and were randomized to CAC score-informed prevention or usual care.

Main Outcomes and Measures

Follow-up CCTA was obtained at 3 years, with plaque volume measured by an independent core laboratory. The primary outcome was total plaque volume, with further analysis for calcified and noncalcified plaque volume.

Results

This study included 365 participants (mean [SD] age, 58 [6] years; 57.5% male); 179 in the CAC score-informed and 186 in the usual care groups. Compared with usual care, the CAC score-informed group showed a sustained reduction in total (mean [SD], -3 [31] mg/dL vs -56 [38] mg/dL; P < .001) and LDL (mean [SD], -2 [31] vs -51 [36] mg/dL; P < .001) cholesterol levels at 3 years, which was associated with a reduction in pooled cohort equation risk calculation (mean [SD], 2.1% [2.9%] vs 0.5% [2.9%]; P < .001). Plaque progression was greater in usual care than CAC score-informed participants for total plaque volume (mean [SD], 24.9 [37.7] mm3 vs 15.4 [30.9] mm3; P = .009), noncalcified plaque volume (mean [SD], 15.7 [32.2] mm3 vs 5.6 [28.5] mm3; P = .002), and fibrofatty and necrotic core plaque volume (mean [SD], 4.5 [25.8] mm3 vs -0.8 [12.6] mm3; P = .02). These plaque volume changes were independent of other risk factors including baseline plaque volume, blood pressure, and lipid profile.

Conclusions and Relevance

The combination of CAC score with a primary prevention strategy in intermediate-risk patients with a family history of CAD was associated with reduction of atherogenic lipids and slower plaque progression compared with usual care. These data support the use of CAC score to assist intensive preventive strategies in intermediate-risk patients.

Trial Registration

anzctr.org.au Identifier: ACTRN12614001294640.