The healing process is a key determinant for postinfarction left ventricular (LV) remodeling and the development of heart failure, which could be influenced by mechanical (pressure and/or volume) load. So far, limited information exists regarding an indepth characterization of the postinfarct healing process in the mechanically unloaded state. In the present work, we performed isogenic Lewis-to-Lewis rat abdominal heterotopic heart transplantation, which is characterized by hemodynamic unloading in the left ventricle, and simultaneously ligated the left anterior descending coronary artery (T-infarct group). Pathological evolution was dynamically compared with that of in situ infarcted Lewis hearts (I-infarct group) on days 3, 7, 14, and 35. There was a remarkable myocardial salvage in the unloaded heart, as shown by the improvement in infarct size (T-infarct group: 25.47% ± 4.31% vs. I-infarct group: 38.46% ± 4.82%, P < 0.01) and the smaller fraction of fibrosis in infarct segments (T-infarct group: 42.12% ± 8.40% vs. I-infarct group: 75.65% ± 10.51%, P < 0.01). In addition, there was a progressive disorganization of the two-dimensional collagen fiber alignment as well as retarded collagen fiber maturation in the T-infarct group. We also observed enhanced angiogenesis, lymphangiogenesis, and inflammatory cell retention in the infarct region during mechanical unloading. Moreover, capillary density and collagen deposition were significantly increased in the noninfarcted area of the unloaded heart compared with the same region in the in situ infarcted heart. In conclusion, ischemic insult in the mechanically unloaded heart elicits an altered inflammatory and healing response, which is characterized by myocardial salvage, delayed resolution of inflammation, and disorganization of the collagen orientation in the infarcted region. These findings could provide novel insights into the contribution of hemodynamic load in the postinfarction healing process. Further studies are warranted to elucidate its potential mechanism.

Salt-loading is an accelerator of hypertensive left ventricular (LV) remodeling. The relationship between salt-loading doses and the time window in which a transition from compensated to decompensated LV hypertrophy occurs in spontaneously hypertensive rats (SHR) is unclear. Eight-week-old male SHR and Wistar Kyoto rats (WKY) were randomized to receive normal (0.5% NaCl) and high salt diets (4% or 8% NaCl) for 12 weeks. Left ventricular remodeling was dynamically determined by echocardiography. LV invasive hemodynamics and morphologic staining [collagen deposition, cardiomyocte hypertrophy, DNA damage (8-hydroxy-2-deoxyguanosine, 8-OHdG) and apoptosis] were performed at time of sacrifice. Cardiac malonyldialdehyde (MDA) level was measured by ELISA. No differences between 4% and 8% salt diets, in terms of blood pressure (BP) levels, heart mass index, and myocardial fibrosis were observed either in SHR or in WKY. In high salt-loaded SHR, the LV ejection fraction and wall thickness peaked at 8 weeks after salt-loading, parallel with a progressive enlargement of the LV chamber size. Furthermore, when compared to 4% salt SHR, LV functions were significantly compromised in 8% salt SHR, accompanied by more prominent cardiomyoctye hypertrophy, oxidative stress (and related DNA damage), and apoptosis. Salt-loading for 12 weeks with 8% NaCl diet is more efficient to induce LV dysfunction than 4% NaCl diet does in SHR, possibly by initiating increased oxidative stress and resultant cardiac damage. Moreover, 8 to 12 weeks after 8% salt-loading is the key time window in which a transition from compensated to decompensated LV hypertrophy occurs.

Pharmacologic inhibition of matrix metalloproteinases (MMP) by doxycycline is of therapeutic potential for a number of cardiovascular diseases characterized by excessive activation of MMP. So far, long-term administration of doxycycline in the treatment of hypertensive ventricular remodeling has not been systemically investigated. Seven-week-old stroke-prone spontaneously hypertensive rats (SHRSP) were fed with doxycycline (30 mgKg(-1) daily) for 26 weeks, when the mortality rate of the control group reached 50%. Stroke incidence was recognized by daily monitoring of stroke symptoms. Left ventricular (LV) performance was measured by in-vivo pressure-volume loop analysis and ex-vivo passive pressure-volume relationship at the time of sacrifice. Collagen deposition, gelatinases activity, protein abundance of gelatinases, and tissue inhibitor of matrix metalloproteinases (TIMP) -1, -2, and related mRNA levels in the heart were determined. MMP-9 expression was not detected in all groups. Excessive activation of MMP-2 in the heart could be partially suppressed by doxycycline. Left ventricular systolic function and ventricular size was partially ameliorated by doxycycline; however, elevated collagen deposition co-existed in the heart. Moreover, doxycycline could downregulate MMP-2 and TIMP-1 expression both at mRNA and protein levels, and TIMP-2 represented opposite expression pattern. These results demonstrate that long-term administration of doxycycline during the development of hypertension has no impact on stroke death, and could partially preserve LV systolic performance and restrain LV chamber dilation, but leads to increased LV extracellular matrix accumulation. Interrupted cardiac MMP-2/TIMP-2 balance by doxycycline may play a role in this process.

Background:The prognostic values of the coronary computed tomography angiography (CCTA) score for predicting future cardiovascular events have been previously demonstrated in numerous studies. However, few studies have used the rich information available from CCTA to detect functionally significant coronary lesions. We sought to compare the prognostic values of Gai's plaque score and the coronary artery calcium score (CACS) of CCTA for predicting functionally significant coronary lesions, using fractional flow reserve (FFR) as the gold standard.Methods:We retrospectively analyzed 107 visually assessed significant coronary lesions in 88 patients (mean age, 59.6 ± 10.2 years; 76.14% of males) who underwent CCTA, invasive coronary angiography, and invasive FFR measurement. An FFR <0.80 indicated hemodynamically significant coronary stenosis. Lesions were divided into two groups using an FFR cutoff value of 0.80. We compared Gai's plaque scores and CACS between the two groups and evaluated the correlations of these scores with FFR. The statistical methods included unpaired t-test, Mann-Whitney U-test, and Spearman's correlation coefficients.Results:Coronary lesions with FFR <0.80 had higher Gai's scores than those with FFR ≥0.80. Gai's score had the strongest correlation with FFR (r = −0.48, P < 0.01) and had a greater area under the curve = 0.72 (95% confidence interval: 0.61–0.82; P < 0.01) than the CACS of whole arteries and a single artery.Conclusions:Both CACS in a single artery and Gai's plaque score demonstrated a good capacity to assess functionally significant coronary artery stenosis when compared to the gold standard FFR. However, Gai's plaque score was more predictive of FFR <0.80. Gai's score can be easily calculated in daily clinical practice and could be used when considering revascularization.

Background: Oral anticoagulation is used extensively for prevention of thromboembolic events. Whether acupuncture is safe for patients taking anticoagulants is not clear. Objective: To describe a patient with a history of ischemic stroke and paroxysmal nonvalvular atrial fibrillation who was in stroke rehabilitation including acupuncture. Design, Setting, and Patient The patient developed sudden calf hematoma when optimal therapeutic intensity of international normalized ratio (INR) was achieved. Results: This patient was treated conservatively, without symptoms of compartment syndrome, and calf hematomas were resolved in 3 months. Conclusions: With increased acceptance of acupuncture worldwide and enforcement of clinical guidelines for prevention of thromboembolism, acupuncture-induced hematoma will be an emerging clinical entity. To minimize hemorrhagic complications, caution should be exercised when patients receiving oral anticoagulation request acupuncture treatment.