Danish phase II trial using adipose tissue derived mesenchymal stromal cells for patients with ischaemic heart failure.

AIMS: Patients suffering from chronic ischaemic heart failure with reduced left ventricular ejection fraction (HFrEF) have reduced quality-of-life, repetitive hospital admissions, and reduced life expectancy. Allogeneic cell therapy is currently investigated as a potential treatment option after initially encouraging results from clinical autologous and allogeneic trials in patients with HFrEF. We aimed to investigate the allogeneic Cardiology Stem Cell Centre Adipose tissue derived mesenchymal Stromal Cell product (CSCC_ASC) as an add-on therapy in patients with chronic HFrEF. METHODS AND RESULTS: This is a Danish multi-centre double-blinded placebo-controlled phase II study with direct intra-myocardial injections of allogeneic CSCC_ASC. A total of 81 HFrEF patients were included and randomized 2:1 to CSCC_ASC or placebo injections. The inclusion criteria were reduced left ventricular ejection fraction (LVEF ≤ 45%), New York Heart Association (NYHA) class II-III despite optimal anti-congestive heart failure medication and no further revascularization options. Injections of 0.3 mL CSCC_ASC (total cell dose 100 × 106 ASCs) (n = 54) or isotonic saline (n = 27) were performed into the viable myocardium in the border zone of infarcted tissue using the NOGA Myostar® catheter (Biological Delivery System, Cordis, Johnson & Johnson, USA). The primary endpoint, left ventricular end systolic volume (LVESV), was evaluated at 6-month follow-up. The safety was measured during a 3-years follow-up period. RESULTS: Mean age was 67.0 ± 9.0 years and 66.6 ± 8.1 years in the ASC and placebo groups, respectively. LVESV was unchanged from baseline to 6-month follow-up in the ASC (125.7 ± 68.8 mL and 126.3 ± 72.5 mL, P = 0.827) and placebo (134.6 ± 45.8 mL and 135.3 ± 49.6 mL, P = 0.855) group without any differences between the groups (0.0 mL (95% CI -9.1 to 9.0 mL, P = 0.992). Neither were there significant changes in left ventricular end diastolic volume or LVEF within the two groups or between groups -5.7 mL (95% CI -16.7 to 5.3 mL, P = 0.306) and -1.7% (95% CI -4.4. to 1.0, P = 0.212), respectively). NYHA classification and 6-min walk test did not alter significantly in the two groups (P > 0.05). The quality-of-life, total symptom, and overall summary score improved significantly only in the ASC group but not between groups. There were 24 serious adverse events (SAEs) in the ASC group and 11 SAEs in the placebo group without any significant differences between the two groups at 1-year follow-up. Kaplan-Meier plot using log-rank test of combined cardiac events showed an overall mean time to event of 30 ± 2 months in the ASC group and 29 ± 2 months in the placebo group without any differences between the groups during the 3 years follow-up period (P = 0.994). CONCLUSIONS: Intramyocardial CSCC_ASC injections in patients with chronic HFrEF were safe but did not improve myocardial function or structure, nor clinical symptoms.

Circulating levels and prognostic cut-offs of sST2, hs-cTnT, and NT-proBNP in women vs. men with chronic heart failure.

AIMS: To define plasma concentrations, determinants, and optimal prognostic cut-offs of soluble suppression of tumorigenesis-2 (sST2), high-sensitivity cardiac troponin T (hs-cTnT), and N-terminal pro-B-type natriuretic peptide (NT-proBNP) in women and men with chronic heart failure (HF). METHODS AND RESULTS: Individual data of patients from the Biomarkers In Heart Failure Outpatient Study (BIOS) Consortium with sST2, hs-cTnT, and NT-proBNP measured were analysed. The primary endpoint was a composite of 1 year cardiovascular death and HF hospitalization. The secondary endpoints were 5 year cardiovascular and all-cause death. The cohort included 4540 patients (age 67 ± 12 years, left ventricular ejection fraction 33 ± 13%, 1111 women, 25%). Women showed lower sST2 (24 vs. 27 ng/mL, P < 0.001) and hs-cTnT level (15 vs. 20 ng/L, P < 0.001), and similar concentrations of NT-proBNP (1540 vs. 1505 ng/L, P = 0.408). Although the three biomarkers were confirmed as independent predictors of outcome in both sexes, the optimal prognostic cut-off was lower in women for sST2 (28 vs. 31 ng/mL) and hs-cTnT (22 vs. 25 ng/L), while NT-proBNP cut-off was higher in women (2339 ng/L vs. 2145 ng/L). The use of sex-specific cut-offs improved risk prediction compared with the use of previously standardized prognostic cut-offs and allowed to reclassify the risk of many patients, to a greater extent in women than men, and for hs-cTnT than sST2 or NT-proBNP. Specifically, up to 18% men and up to 57% women were reclassified, by using the sex-specific cut-off of hs-cTnT for the endpoint of 5 year cardiovascular death. CONCLUSIONS: In patients with chronic HF, concentrations of sST2 and hs-cTnT, but not of NT-proBNP, are lower in women. Lower sST2 and hs-cTnT and higher NT-proBNP cut-offs for risk stratification could be used in women.

Cardiac biomarkers retain prognostic significance in patients with heart failure and chronic obstructive pulmonary disease.

AIMS: Chronic obstructive pulmonary disease (COPD) is a frequent comorbidity in patients with heart failure (HF). We assessed the influence of COPD on circulating levels and prognostic value of three HF biomarkers: N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity troponin T (hs-TnT), and soluble suppression of tumorigenesis-2 (sST2). METHODS: Individual data from patients with chronic HF, known COPD status, NT-proBNP and hs-TnT values (n = 8088) were analysed. A subgroup (n = 3414) had also sST2 values. RESULTS: Patients had a median age of 66 years (interquartile interval 57-74), 77% were men and 82% had HF with reduced ejection fraction. NT-proBNP, hs-TnT and sST2 were 1207 ng/l (487-2725), 17 ng/l (9-31) and 30 ng/ml (22-44), respectively. Patients with COPD (n = 1249, 15%) had higher NT-proBNP (P = 0.042) and hs-TnT (P < 0.001), but not sST2 (P = 0.165). Over a median 2.0-year follow-up (1.5-2.5), 1717 patients (21%) died, and 1298 (16%) died from cardiovascular causes; 2255 patients (28%) were hospitalized for HF over 1.8 years (0.9-2.1). NT-proBNP, hs-TnT and sST2 predicted the three end points regardless of COPD status. The best cut-offs from receiver-operating characteristics analysis were higher in patients with COPD than in those without. Patients with all three biomarkers higher than or equal to end-point- and COPD-status-specific cut-offs were also those with the worst prognosis. CONCLUSIONS: Among patients with HF, those with COPD have higher NT-proBNP and hs-TnT, but not sST2. All these biomarkers yield prognostic significance regardless of the COPD status.

Impaired coronary flow velocity reserve is associated with cardiovascular risk factors but not with angina symptoms.

OBJECTIVES: Coronary microvascular dysfunction (CMD) is considered to cause angina pectoris in a large proportion of women with no obstructive coronary artery disease (CAD). However, data supporting a relation between angina pectoris and CMD are limited. We compared CMD in women with angina with asymptomatic women and evaluated the relation between presence of CMD, angina characteristics, cardiovascular risk factors and results of stress testing. METHODS: In a cross-sectional study, we included 1684 women with angina and <50% coronary artery stenosis on invasive angiography. Asymptomatic women from the community-based Copenhagen City Heart Study served as reference group (n=102). Coronary microvascular function was determined by coronary flow velocity reserve (CFVR) assessed by transthoracic Doppler stress echocardiography. CFVR < 2 was defined as CMD. Symptoms were obtained from standardised angina questionnaires and results of stress testing from health records. RESULTS: Median CFVR was 2.33 (IQR 2.00-2.75) in symptomatic women versus 2.60 (2.19-2.95) in asymptomatic (p=0.007). CFVR <2 was found in 25% of symptomatic and in 19% of asymptomatic women. Symptomatic women had a greater risk factor burden. After adjusting for age, hypertension, diabetes, smoking and heart rate the difference in CFVR between groups disappeared (p=0.213). We found no associations between CFVR and angina characteristics, symptom burden or results from stress testing. CONCLUSIONS: Impaired CFVR is more prevalent in symptomatic than in asymptomatic women and related to the cardiovascular risk factors hypertension, diabetes, smoking and increased heart rate. Neither a positive bicycle test, single photon emission CT stress test nor chest pain characteristics identify women with impaired CFVR among women with angina and no obstructive CAD. Results may question the concept of microvascular angina as currently defined.

Myocardial CT perfusion compared with transthoracic Doppler echocardiography in evaluation of the coronary microvascular function: An iPOWER substudy.

BACKGROUND: A significant number of women with angina and no obstructive coronary artery disease (CAD; <50% stenosis) have coronary microvascular dysfunction (CMD) which carries an adverse cardiovascular prognosis. Coronary microvascular function can be evaluated by transthoracic Doppler echocardiography (TTDE) as a coronary flow velocity reserve (CFVR) and by static CT myocardial perfusion (CTP) as a myocardial perfusion reserve (MPR). Whether these methods are correlated is not known. We assessed the correlation between CFVR and MPR and investigated whether women with angina, CMD and no obstructive CAD have reduced MPR compared with asymptomatic women. METHODS: Static CTP with adenosine-induced vasodilation and TTDE of the left anterior descending artery with dipyridamole-induced vasodilation were successfully performed and analysed in 99 women with stable angina and no obstructive CAD and 33 asymptomatic women with no obstructive CAD. CMD was defined as CFVR < 2. RESULTS: Correlation between rate-pressure product corrected MPR and CFVR was weak but significant (r = .23; p = .007). MPR was highest among asymptomatic women with normal CFVR (median [interquartile range; IQR] 158 [145-181] %). Symptomatic women with normal CFVR had reduced MPR (148 [134-162] %; age-adjusted p < .001); however, the lowest MPR was found in symptomatic women with CMD (140 [129-164] %; age-adjusted p < .001), independent of cardiovascular risk factors and haemodynamic parameters (p = .017). CONCLUSION: Women with angina, CMD and no obstructive CAD had markedly diminished MPR compared with asymptomatic women. Correlation between CFVR and MPR was weak, suggesting that CTP and TTDE are not interchangeable for detection of CMD.

The First Steps Taken to Implement Palliative Care in Advanced Heart Disease: A Position Statement from Denmark.

According to the World Health Organization, palliative care must be available for everyone with life-threatening diseases. However, in daily practice the primary focus worldwide is on cancer patients. The aim of the article was to generate a national position statement as the first step in implementing palliative care in severe heart disease with focus on advanced heart failure, including tools to identify the need for and timing of palliative care and how palliative care could be organized in Denmark. A task force was formed in the Danish Society of Cardiology Heart Failure Working Group, and the position statement was prepared in collaboration with members from a broad group of specialties, including palliative medicine. Because of major gaps in evidence, the position statement was based on small and low-quality studies and clinical practice statements. This position statement was aligned with the European Society of Cardiology recommendation, focusing on relieving suffering from the early disease stages parallel to standard care and supplementing life-prolonging treatment. The statement delivers practical guidance on clinical aspects and managing symptoms during the three stages of advanced heart disease. Furthermore, the statement describes the importance of communication and topics to be broached, including deactivating implantable cardioverter defibrillators. The statement recommends a targeted effort on organizational strategies using high-quality assessment tools and emphasizes multidisciplinary and intersectoral collaboration. Danish cardiologists supported by allied professionals acknowledge the importance of palliative care in advanced heart disease. This national position statement intended to inform and influence policy and practice and can hopefully inspire other countries to take action toward implementing palliative care in advanced heart disease.

Circulating levels and prognostic value of soluble ST2 in heart failure are less influenced by age than N-terminal pro-B-type natriuretic peptide and high-sensitivity troponin T.

AIMS: N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity troponin T (hs-TnT) and soluble suppression of tumorigenesis-2 (sST2) predict outcome in chronic heart failure (HF). We assessed the influence of age on circulating levels and prognostic significance of these biomarkers. METHODS AND RESULTS: Individual data from 5301 patients with chronic HF and NT-proBNP, hs-TnT, and sST2 data were evaluated. Patients were stratified according to age: <60 years (n = 1332, 25%), 60-69 years (n = 1628, 31%), 70-79 years (n = 1662, 31%), and ≥ 80 years (n = 679, 13%). Patients (median age 66 years, 75% men, median left ventricular ejection fraction 28%, 64% with ischaemic HF) had median NT-proBNP 1564 ng/L, hs-TnT 21 ng/L, and sST2 29 ng/mL. Age independently predicted NT-proBNP and hs-TnT, but not sST2. The best NT-proBNP and hs-TnT cut-offs for 1-year and 5-year all-cause and cardiovascular mortality and 1- to 12-month HF hospitalization increased with age, while the best sST2 cut-offs did not. When stratifying patients according to age- and outcome-specific cut-offs, this stratification yielded independent prognostic significance over NT-proBNP levels only, or the composite of NT-proBNP and hs-TnT, and improved risk prediction for most endpoints. Finally, absolute NT-proBNP, hs-TnT, and sST2 levels predicted outcomes independent of age, sex, left ventricular ejection fraction category, ethnic group, and other variables. CONCLUSIONS: Soluble ST2 is less influenced by age than NT-proBNP or hs-TnT; all these biomarkers predict outcome regardless of age. The use of age- and outcome-specific cut-offs of NT-proBNP, hs-TnT and sST2 allows more accurate risk stratification than NT-proBNP alone or the combination of NT-proBNP and hs-TnT.

Prevalence and diagnostic outcomes of children with duodenal lesions and negative celiac serology.

BACKGROUND: Celiac disease diagnostics begin by measuring autoantibodies, which may fail to identify seronegative patients. Duodenal lesion in the absence of antibodies is scarcely studied, especially in children. AIMS: To investigate the prevalence and diagnostic outcomes of children with seronegative duodenal lesion in two countries with different disease profiles. METHODS: Medical data, including the results of histology and transglutaminase (tTGab) and endomysium (EmA) antibody measurements were collected from 1172 Finnish and 264 Romanian children with systematic duodenal sampling. Database of 509 Finnish children with celiac disease was examined to identify earlier seronegative patients. RESULTS: Celiac disease was diagnosed in 307 Finnish and 83 Romanian children in the endoscopy cohorts. No seronegative patients were found among 899 celiac disease patients, although some were only tTGab or EmA positive. Non-celiac duodenal lesion was detected in eight Finnish and 32 Romanian children, their most common diagnoses being inflammatory bowel disease and infections, respectively. Six children with morphological lesion received no diagnosis. None of them developed celiac disease during a follow-up of 3-11 years. CONCLUSION: Pediatric seronegative celiac disease is exceptional in the era of modern autoantibodies. Other reasons for duodenal lesion should therefore be sought, bearing in mind possible differences across countries.

Evaluation of computed tomography myocardial perfusion in women with angina and no obstructive coronary artery disease.

Women with angina and no obstructive coronary artery disease (CAD) have worse cardiovascular prognosis than asymptomatic women. Limitation in myocardial perfusion caused by coronary microvascular dysfunction (CMD) is one of the proposed mechanisms contributing to the adverse prognosis. The aim of this study was to assess myocardial perfusion in symptomatic women with no obstructive CAD suspected for CMD compared with asymptomatic sex-matched controls using static CT perfusion (CTP). We performed a semi-quantitative assessment of the left ventricular myocardial perfusion and myocardial perfusion reserve (MPR), using static CTP with adenosine provocation, in 105 female patients with angina and no obstructive CAD (< 50% stenosis) and 33 sex-matched controls without a history of angina or ischemic heart disease.  Patients were on average 4 years older (p = 0.04) and had a higher burden of cardiovascular risk factors. While global perfusion during rest was comparable between the groups (age-adjusted p = 0.12), global perfusion during hyperemia was significantly reduced in patients compared with controls (163 ± 23 HU vs. 171 ± 25 HU; age-adjusted p = 0.023). The ability to increase myocardial perfusion during adenosine-induced vasodilation was significantly diminished in patients (MPR 148% vs. 158%; age-adjusted p < 0.001). This remained unchanged after adjustment for cardiovascular risk factors (p = 0.008). Women with angina and no obstructive CAD have reduced hyperemic myocardial perfusion and MPR compared with sex-matched controls. Impaired myocardial perfusion may be related to the presence of CMD in some of these women.

Revisiting the obesity paradox in heart failure: Per cent body fat as predictor of biomarkers and outcome.

AIMS: Obesity defined by body mass index (BMI) is characterized by better prognosis and lower plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) in heart failure. We assessed whether another anthropometric measure, per cent body fat (PBF), reveals different associations with outcome and heart failure biomarkers (NT-proBNP, high-sensitivity troponin T (hs-TnT), soluble suppression of tumorigenesis-2 (sST2)). METHODS: In an individual patient dataset, BMI was calculated as weight (kg)/height (m) 2 , and PBF through the Jackson-Pollock and Gallagher equations. RESULTS: Out of 6468 patients (median 68 years, 78% men, 76% ischaemic heart failure, 90% reduced ejection fraction), 24% died over 2.2 years (1.5-2.9), 17% from cardiovascular death. Median PBF was 26.9% (22.4-33.0%) with the Jackson-Pollock equation, and 28.0% (23.8-33.5%) with the Gallagher equation, with an extremely strong correlation (r = 0.996, p < 0.001). Patients in the first PBF tertile had the worst prognosis, while patients in the second and third tertile had similar survival. The risks of all-cause and cardiovascular death decreased by up to 36% and 27%, respectively, per each doubling of PBF. Furthermore, prognosis was better in the second or third PBF tertiles than in the first tertile regardless of model variables. Both BMI and PBF were inverse predictors of NT-proBNP, but not hs-TnT. In obese patients (BMI ≥ 30 kg/m2, third PBF tertile), hs-TnT and sST2, but not NT-proBNP, independently predicted outcome. CONCLUSION: In parallel with increasing BMI or PBF there is an improvement in patient prognosis and a decrease in NT-proBNP, but not hs-TnT or sST2. hs-TnT or sST2 are stronger predictors of outcome than NT-proBNP among obese patients.

Myocardial first pass perfusion assessed by cardiac magnetic resonance and coronary microvascular dysfunction in women with angina and no obstructive coronary artery disease.

Coronary microvascular dysfunction (CMD) is associated with a poor prognosis even in absence of obstructive coronary artery disease. CMD can be assessed as a myocardial blood flow reserve by positron emission tomography (PETMBFR) and as coronary flow velocity reserve by transthoracic Doppler echocardiography (TTDECFVR). Impaired first-pass perfusion assessed by cardiac magnetic resonance (CMR) is an early sign of ischemia. We aimed to investigate the association between CMD and CMR first-pass perfusion. Women (n = 66) with angina pectoris and an invasive coronary angiogram (<50% stenosis) were assessed by TTDECFVR and in a subgroup of these (n = 54) also by PETMBFR. Semi-quantitative evaluation of first-pass perfusion at rest and adenosine stress was assessed by gadolinium CMR in all 66 women. Four measures of CMR perfusion reserve were calculated using contrast upslope, maximal signal intensity and both indexed to arterial input. Mean (standard deviation) age was 62 (8) years. Median (interquartile range) TTDECFVR was 2.3 (1.8;2.7) and PETMBFR was 2.7 (2.2;3.1). Using a cut-off of 2.0 for TTDECFVR and 2.5 for PETMBFR, 25 (38%) and 21 (39%) had CMD, respectively. CMR myocardial perfusion reserve from contrast upslope (CMR_MPRupslope) showed moderate but significant correlation with PETMBFR (R = .46, p < .001) while none of the other CMR variables were associated with CMD. A CMR_MPRupslope cut-off of 0.78 identified CMD, area under the curve 0.73 (p = .001). The results indicate that CMR_MPRupslope may be associated to PETMBFR; a measure of CMD. Further research is needed to validate and implement the use of CMR first pass perfusion in this population.

Myocardial perfusion assessed with cardiac computed tomography in women without coronary heart disease.

PURPOSE: Combined coronary CT angiography and CT perfusion (CTP) is a novel, non-invasive, 'one-stop' diagnostic tool to rule out ischaemia in patients suspected for coronary artery disease (CAD). However, the normal myocardial perfusion pattern by static CTP in humans is poorly described. We aimed to investigate global and regional myocardial perfusion during rest and adenosine-induced hyperaemia in asymptomatic women without history of coronary heart disease (CHD). METHODS: Using a 320-row CT scanner with a static protocol, semi-quantitative assessment of rest and stress CTP was performed in 34 asymptomatic middle-aged women without obstructive CAD (<50% stenosis) or history of CHD, and with normal exercise stress test and left ventricular (LV) function. Using a 16-segment model, we assessed global and regional values of LV myocardial perfusion reserve (MPR) and transmural perfusion ratio (TPR). RESULTS: Mean±SD age was 56 ± 13 years. Resting and hyperaemic myocardial perfusion was heterogeneously distributed throughout the LV myocardium. During hyperaemia, global MPR increased by median (IQR) 158% (144-176) with the highest increase in the right coronary artery territory (171%; P<0.02). Rest and stress segmental TPR values ranged between 0.93-1.26 and 0.99-1.13, respectively, with the lowest values detected in the inferoseptal segments. No differences in perfusion parameters were found between participants with normal epicardial arteries and participants with non-significant epicardial atheromatosis (all P>0.05). Global perfusion parameters were not associated with age or menopausal status (all P>0.05). CONCLUSIONS: This descriptive study presents data on global and regional myocardial perfusion in a cohort of healthy middle-aged women.

Transthoracic Doppler echocardiography compared with positron emission tomography for assessment of coronary microvascular dysfunction: The iPOWER study.

BACKGROUND: Coronary microvascular function can be assessed by transthoracic Doppler echocardiography as a coronary flow velocity reserve (TTDE CFVR) and by positron emission tomography as a myocardial blood flow reserve (PET MBFR). PET MBFR is regarded the noninvasive reference standard for measuring coronary microvascular function but has limited availability. We compared TTDE CFVR with PET MBFR in women with angina pectoris and no obstructive coronary artery disease and assessed repeatability of TTDE CFVR. METHODS: From a cohort of women with angina and no obstructive coronary artery stenosis at invasive coronary angiography, TTDE CFVR by dipyridamole induced stress and MBFR by rubidium-82 PET with adenosine was successfully measured in 107 subjects. Repeatability of TTDE CFVR was assessed in 10 symptomatic women and in 10 healthy individuals. RESULTS: MBFR was systematically higher than CFVR. Median MBFR (interquartile range, IQR) was 2.68 (2.29-3.10) and CFVR (IQR) was 2.31 (1.89-2.72). Pearson's correlation coefficient was 0.36 (p<0.01). Limits of agreement (2·standard deviation) assessed by the Bland-Altman (confidence interval, CI) method was 1.49 (1.29;1.69) and unaffected by time-interval between examinations. Results were similar when adjusting for rate pressure product or focusing on perfusion of the left anterior descending artery region. Limits of agreement (CI) for repeated CFVR in 10 healthy individuals and in 10 women with angina was 0.44 (0.21;0.68) and 0.48 (0.22; 0.74), respectively. CONCLUSION: CFVR had a good repeatability, but the agreement between CFVR and MBFR was modest. Divergence could be due to methodology differences; TTDE estimates flow velocities whereas PET estimates myocardial blood flow.

Coronary Microvascular Function and Cardiovascular Risk Factors in Women With Angina Pectoris and No Obstructive Coronary Artery Disease: The iPOWER Study.

BACKGROUND: The majority of women with angina-like chest pain have no obstructive coronary artery disease when evaluated with coronary angiography. Coronary microvascular dysfunction is a possible explanation and associated with a poor prognosis. This study evaluated the prevalence of coronary microvascular dysfunction and the association with symptoms, cardiovascular risk factors, psychosocial factors, and results from diagnostic stress testing. METHODS AND RESULTS: After screening 3568 women, 963 women with angina-like chest pain and a diagnostic coronary angiogram without significant coronary artery stenosis (<50%) were consecutively included. Mean age (SD) was 62.1 (9.7). Assessment included demographic and clinical data, blood samples, questionnaires, and transthoracic echocardiography during rest and high-dose dipyridamole (0.84 mg/kg) with measurement of coronary flow velocity reserve (CFVR) by Doppler examination of the left anterior descending coronary artery. CFVR was successfully measured in 919 (95%) women. Median (IQR) CFVR was 2.33 (1.98-2.76), and 241 (26%) had markedly impaired CFVR (<2). In multivariable regression analysis, predictors of impaired CFVR were age (P<0.01), hypertension (P=0.02), current smoking (P<0.01), elevated heart rate (P<0.01), and low high-density lipoprotein cholesterol (P=0.02), but these variables explained only a little of the CFVR variation (r(2)=0.09). CFVR was not associated with chest pain characteristics or results from diagnostic stress testing. CONCLUSION: Impaired CFVR was detected in a substantial proportion, which suggests that coronary microvascular dysfunction plays a role in the development of angina pectoris. CFVR was associated with few cardiovascular risk factors, suggesting that CFVR is an independent parameter in the risk evaluation of these women. Symptom characteristics and results from stress testing did not identify individuals with impaired CFVR.

Carbachol-induced MUC17 endocytosis is concomitant with NHE3 internalization and CFTR membrane recruitment in enterocytes.

We have reported that transmembrane mucin MUC17 binds PDZ protein PDZK1, which retains MUC17 apically in enterocytes. MUC17 and transmembrane mucins MUC3 and MUC12 are suggested to build the enterocyte apical glycocalyx. Carbachol (CCh) stimulation of the small intestine results in gel-forming mucin secretion from goblet cells, something that requires adjacent enterocytes to secrete chloride and bicarbonate for proper mucin formation. Surface labeling and confocal imaging demonstrated that apically expressed MUC17 in Caco-2 cells and Muc3(17) in murine enterocytes were endocytosed upon stimulation with CCh. Relocation of MUC17 in response to CCh was specific as MUC3 and MUC12 did not relocate following CCh stimulation. MUC17 colocalized with PDZK1 under basal conditions, while MUC17 relocated to the terminal web and into early endosomes after CCh stimulation. CCh stimulation concomitantly internalized the Na(+/)H(+) exchanger 3 (NHE3) and recruited cystic fibrosis transmembrane conductance regulator (CFTR) to the apical membranes, a process that was important for CFTR-mediated bicarbonate secretion necessary for proper gel-forming mucin unfolding. The reason for the specific internalization of MUC17 is not understood, but it could limit the diffusion barrier for ion secretion caused by the apical enterocyte glycocalyx or alternatively act to sample luminal bacteria. Our results reveal well-orchestrated mucus secretion and trafficking of ion channels and the MUC17 mucin.