Continuous positive airway pressure improves blood pressure and serum cardiovascular biomarkers in obstructive sleep apnoea and hypertension.

BACKGROUND: The impact of treatment for obstructive sleep apnoea (OSA) on reduction of cardiovascular risk is unclear. This study aimed to examine the effect of continuous positive airway pressure (CPAP) on ambulatory blood pressure (BP) and subclinical myocardial injury in subjects with OSA and hypertension. METHODS: This was a parallel-group randomised controlled trial. Subjects with hypertension requiring at least three antihypertensive medications and moderate-to-severe OSA were enrolled. Eligible subjects were randomised (1:1) to receive either CPAP treatment or control (no CPAP) for 8 weeks. Changes in ambulatory BP and serum biomarkers were compared. Stratified analysis according to circadian BP pattern was performed. RESULTS: 92 subjects (75% male; mean±sd age 51±8 years and apnoea-hypopnoea index 40±8 events·h-1, taking an average of 3.4 (range 3-6) antihypertensive drugs) were randomised. The group on CPAP treatment, compared with the control group, demonstrated a significant reduction in 24-h systolic BP (-4.4 (95% CI -8.7- -0.1) mmHg; p=0.046), 24-h diastolic BP (-2.9 (95% CI -5.5- -0.2) mmHg; p=0.032), daytime systolic BP (-5.4 (95% CI -9.7- -1.0) mmHg; p=0.016) and daytime diastolic BP (-3.4 (95% CI -6.1- -0.8) mmHg; p=0.012). CPAP treatment was associated with significant BP lowering only in nondippers, but not in dippers. Serum troponin I (mean difference -1.74 (95% CI -2.97- -0.50) pg·mL-1; p=0.006) and brain natriuretic peptide (-9.1 (95% CI -17.6- -0.6) pg·mL-1; p=0.036) were significantly reduced in CPAP compared with the control group. CONCLUSIONS: In a cohort with OSA and multiple cardiovascular risk factors including difficult-to-control hypertension, short-term CPAP treatment improved ambulatory BP, and alleviated subclinical myocardial injury and strain.

The comparison of short-term prognostic value of T1 mapping with feature tracking by cardiovascular magnetic resonance in patients with severe dilated cardiomyopathy.

To evaluate and compare the prognostic value of T1 mapping with feature tracking cardiovascular magnetic resonance (FT-CMR) imaging in patients with severe dilated cardiomyopathy (DCM) during short-term follow-up. A total of 46 patients with severe DCM (LVEF < 35%) underwent 3.0-T CMR with T1 mapping and FT-CMR analysis. The study end-point was defined as a combination of cardiac death, heart transplantation, and hospitalization due to cardiovascular events. The significance of the risk factors was mainly evaluated by univariate and multivariate Cox model analyses. During the median follow-up of 13 months (interquartile range 7-17 months), two patients died of heart failure, one received a heart transplantation, and six were hospitalized for heart failure. In the univariate analysis, extracellular volume fraction (ECV) showed significant predictive association with cardiovascular events (hazard ratio [HR] 1.35; 95% confidence interval [CI] 1.13-1.62; P = 0.001). No strain parameters in FT-CMR differed significantly between patients with or without events (all P > 0.05). In the multivariate analyses, ECV was the sole independent predictor of cardiovascular events (HR, 1.48; 95% CI 1.13-1.94; P = 0.005). The area under the curve of the time-dependent receiver operating characteristic in leave-one-out cross-validation (all > 0.70) further confirmed the predictive significance of ECV. In patients with severe DCM, ECV was not only a strong independent predictor of adverse cardiovascular events but also provided prognostic value prior to strain parameters of the FT-CMR in the short term.

Incremental prognostic value of global longitudinal strain in patients with type 2 diabetes mellitus.

BACKGROUND: Patients with type 2 diabetes mellitus (T2DM) are at high risk for cardiovascular events. The aim of the study was to assess whether global longitudinal strain (GLS) provides prognostic value in these patients. METHODS: A total of 247 T2DM patients without history of cardiovascular complications and participated in the CDATS study were prospectively enrolled. Left ventricular (LV) systolic function was assessed by LV ejection fraction and speckle tracking derived LV systolic GLS. Diastolic function was assessed by E/E' ratio defined as the passive trans-mitral LV inflow velocity to tissue Doppler imaging velocity of the medial mitral annulus. Cardiovascular event included acute coronary syndrome, cerebrovascular stroke, hospitalization for heart failure and cardiovascular death. RESULTS: A total of 18 cardiovascular events occurred during a median follow-up duration of 33 months. Both E/E' ratio [hazard ratio (HR) 1.15, P < 0.01] and GLS (HR 1.39, P < 0.01) were independently associated with cardiovascular events. Importantly, GLS provided incremental prognostic information in addition to clinical data, HbA1c and E/E' ratio (Chi square 77.46, P = 0.04). Receiver-operator characteristic curve analysis demonstrated that E/E' ratio [area under curve (AUC) 0.66, P = 0.03] and GLS (AUC 0.72, P < 0.01) were strong predictors of cardiovascular events. Kaplan-Meier analysis showed that patients with E/E' > 13.6 or GLS > -17.9 % were associated with cardiovascular events. The presence of either a high E/E' ratio or an impaired GLS provides an excellent negative predictive value of cardiovascular events in these patients. CONCLUSIONS: In T2DM patients with no history of cardiovascular disease, impaired GLS was associated with cardiovascular events and provided incremental prognostic value.

Increased T-wave alternans is associated with subclinical myocardial structural and functional abnormalities in patients with type 2 diabetes.

BACKGROUND: Increased T wave alternans (TWA) represents ventricular depolarization heterogeneity and is a non-invasive marker of sudden cardiac death. This study sought to determine whether myocardial structural alteration and dysfunction in patients with type 2 diabetes mellitus (T2DM) is associated with an increased TWA. METHODS: We recruited 108 T2DM patients (59.2±9.7 years and 52% male) without prior history of cardiovascular disease and normal treadmill stress testing. TWA was analyzed during treadmill testing in all standard precordial leads by time-domain method. Transthoracic echocardiography was performed to measure myocardial structural alteration by calibrated integrated backscatter (IBS), left ventricular (LV) systolic function by conventional method, and speckle tracking-derived global longitudinal strain (GLS), and LV diastolic function. RESULTS: A total of 29 (26.9%) patients had a high TWA of ≥47mV (defined by ≥75 percentile of the study population). Patients with and without elevated TWA had a similar LV dimension and ejection fraction. Nonetheless, patients with high TWA had a higher calibrated IBS (-15.8±4.0dB vs. -17.9±5.3dB, p=0.04), more impaired GLS (-18.4±2.0% vs. -19.3±1.4%, p=0.02), and a higher prevalence of diastolic dysfunction (60 vs. 33%, p=0.02). Multivariable analysis demonstrated that high TWA was independently associated with calibrated IBS, GLS, and LV diastolic dysfunction grading. CONCLUSIONS: Our results demonstrated that calibrated IBS, GLS, and LV diastolic dysfunction are independent predictors for high TWA in T2DM patients. These findings suggest that subclinical myocardial structural and functional abnormalities may contribute to high TWA in T2DM patients.

Improvement of myocardial perfusion reserve detected by cardiovascular magnetic resonance after direct endomyocardial implantation of autologous bone marrow cells in patients with severe coronary artery disease.

BACKGROUND: Recent studies suggested that bone marrow (BM) cell implantation in patients with severe chronic coronary artery disease (CAD) resulted in modest improvement in symptoms and cardiac function. This study sought to investigate the functional changes that occur within the chronic human ischaemic myocardium after direct endomyocardial BM cells implantation by cardiovascular magnetic resonance (CMR). METHODS AND RESULTS: We compared the interval changes of left ventricular ejection fraction (LVEF), myocardial perfusion reserve and the extent of myocardial scar by using late gadolinium enhancement CMR in 12 patients with severe CAD. CMR was performed at baseline and at 6 months after catheter-based direct endomyocardial autologous BM cell (n = 12) injection to viable ischaemic myocardium as guided by electromechanical mapping. In patients randomized to receive BM cell injection, there was significant decrease in percentage area of peri-infarct regions (-23.6%, P = 0.04) and increase in global LVEF (+9.0%, P = 0.02), the percentage of regional wall thickening (+13.1%, P= 0.04) and MPR (+0.25%, P = 0.03) over the target area at 6-months compared with baseline. CONCLUSIONS: Direct endomyocardial implantation of autologous BM cells significantly improved global LVEF, regional wall thickening and myocardial perfusion reserve, and reduced percentage area of peri-infarct regions in patients with severe CAD.

Value of ST-segment depression in lead V4R in predicting proximal against distal left circumflex artery occlusion in acute inferoposterior myocardial infarction.

BACKGROUND: Lead V(4R) faces the right ventricular free wall; it also reflects ischemia in the posterolateral wall lying opposite and manifests as ST-segment depression. HYPOTHESIS: The aim of this study was to evaluate the usefulness of V(4R) ST-segment depression in distinguishing proximal from distal left circumflex artery occlusion in acute inferoposterior wall myocardial infarction. METHODS: We retrospectively analyzed 239 patients who had first acute inferoposterior myocardial infarction, were admitted within 6 h from onset of symptom, and had coronary angiography performed within 4 weeks. Patients who had bundle-branch block or concomitant significant stenoses in the proximal and distal segments of the same vessel or of both vessels were excluded. The electrocardiographic and angiographic findings were reviewed by two independent groups of investigators. RESULTS: V(4R) ST-segment depression > or =1.0 mm was found in 8 of 46 patients (17.4%) with left circumflex artery occlusion but none (0%) with right coronary artery occlusion. Among the group with left circumflex artery occlusion, the mean magnitude of V(4R) ST-segment depression was greater in proximal than distal occlusion (0.82 +/- 0.65 vs. 0.03 +/- 0.12 mm, p < 0.0001). V(4R)ST-segment depression > or =1.0 mm was found in 8 of 14 patients (57.1%) with proximal occlusion but none (0%) in 32 patients with distal occlusion. The sensitivity and specificity to predict proximal occlusion were 57.1 and 100%, respectively. CONCLUSIONS: V(4R) ST-segment depression > or =1.0 mm was not useful for differentiating left circumflex and right coronary artery occlusion because of its low sensitivity. It is a fairly sensitive and very specific sign of proximal left circumflex artery occlusion.