Long-Term Outcomes of Bovine versus Porcine Mitral Valve Replacement: A Multicenter Analysis.

Introduction: Recent national guidelines recommending mitral valve replacement (MVR) for severe secondary mitral regurgitation have resulted in an increased utilization of mitral bioprosthesis. There is a paucity of data on how longitudinal clinical outcomes vary by prosthesis type. We examined long-term survival and risk of reoperation between patients having bovine vs. porcine MVR. Study Design. A retrospective analysis of MVR or MVR + coronary artery bypass graft (CABG) from 2001 to 2017 among seven hospitals reporting to a prospectively maintained clinical registry was conducted. The analytic cohort included 1,284 patients undergoing MVR (801 bovine and 483 porcine). Baseline comorbidities were balanced using 1 : 1 propensity score matching with 432 patients in each group. The primary end point was all-cause mortality. Secondary end points included in-hospital morbidity, 30-day mortality, length of stay, and risk of reoperation. Results: In the overall cohort, patients receiving porcine valves were more likely to have diabetes (19% bovine vs. 29% porcine; p < 0.001), COPD (20% bovine vs. 27% porcine; p=0.008), dialysis or creatinine >2 mg/dL (4% bovine vs. 7% porcine; p=0.03), and coronary artery disease (65% bovine vs. 77% porcine; p < 0.001). There was no difference in stroke, acute kidney injury, mediastinitis, pneumonia, length of stay, in-hospital morbidity, or 30-day mortality. In the overall cohort, there was a difference in long-term survival (porcine HR 1.17 (95% CI: 1.00-1.37; p=050)). However, there was no difference in reoperation (porcine HR 0.56 (95% CI: 0.23-1.32; p=0.185)). In the propensity-matched cohort, patients were matched on all baseline characteristics. There was no difference in postoperative complications or in-hospital morbidity and 30-day mortality. After 1 : 1 propensity score matching, there was no difference in long-term survival (porcine HR 0.97 (95% CI: 0.81-1.17; p=0.756)) or risk of reoperation (porcine HR 0.54 (95% CI: 0.20-1.47; p=0.225)). Conclusions: In this multicenter analysis of patients undergoing bioprosthetic MVR, there was no difference in perioperative complications and risk of reoperation of long-term survival after matching.

Bleeding versus thrombosis: role of short DAPT in complex lesions.

Therapy with dual antiplatelet agents, defined as the combination of a platelet P2Y12 inhibitor and aspirin, is required to prevent thrombotic complications, after percutaneous coronary intervention (PCI) with stent implantation. Usually current guidelines recommend administration of dual antiplatelet therapy (DAPT) following percutaneous revascularization with drug-eluting stent (DES) for a period of at least 12 months or for 6 to 12 months in patients not at high risk. Nevertheless, the treatment of stable/unstable coronary artery disease with DES implantation increasing largely, the optimal duration of DAPT is still unclear. The duration of DAPT after coronary stenting has been evaluated in recent randomized studies with conflicting results. The administration of long period of DAPT is a strategy to reduce thrombosis events but largely increase the hemorrhagic ones. Otherwise, shorter DAPT period is protective about bleeds with consequently increased ischemic events. In addition, as new DES carry a lower risk of stent thrombosis (ST) compared with the first-generation DES and possibly even bare-metal stents, a shift toward better protection from ST may have an effect on the duration and the intensity of DAPT. Whether the duration of DAPT should be shorter or longer than the currently recommended 6 to 12 months is analyzed in this review, drawing on results from the most recent studies and meta-analysis.

Accumulation of polycyclic aromatic hydrocarbons by lichen transplants: Comparison with gas-phase passive air samplers.

This study compared the accumulation of 16 polycyclic aromatic hydrocarbons (PAHs) in samples of the lichen Evernia prunastri exposed for 3 months in and around an industrial area of S Italy with that in co-located passive gas-phase air samplers. The results showed a strong linear correlations (R=0.96, P<0.05) between total PAHs in lichens and in passive samplers, clearly indicating that lichen transplants may provide direct quantitative information on the atmospheric load by total PAHs, allowing translation of lichen values into atmospheric concentrations. To the best of our knowledge this is the first study reporting such a correlation with gas-phase passive air samplers.

Results of the self-expandable BA9 stent for treatment of large angle coronary bifurcation.

Since the advent of coronary angioplasty the treatment of bifurcation lesions has always proved a complex issue resulting in lower angiographic success rates, increased risk of restenosis, higher rates of dissection, myocardial infarction, and acute vessel closure. The advent of coronary stenting reduced the risks, but in-stent restenosis was noted to be frequent at the ostium of the side branch; for this reasons two-stent techniques were developed to try to combat this phenomenon. Novel dedicated stents have recently been developed to provide easier access to the SB and to scaffold more effectively its ostium, matching the stent configuration more closely to the anatomy of the bifurcation. Most of bifurcation lesions that require treatment and which have a wide angle involving the left main coronary artery (LMCA). The impact of the angle and the asymmetry of bifurcation on flow dynamic are very important and may influence clinical outcome. More recently, percutaneous coronary intervention (PCI) to treat wide angle disease has increased in frequency, and is associated with improvements in interventional techniques and adjunctive drug therapy. Several studies have shown that stenting in LMCA, especially using drug-eluting stents (DES), is a safe and effective treatment strategy both at mid- and long-term follow-up. The AXXESS System is a self-expanding, conically-shaped stent from nitinol (nickel-titanium alloy) with strut thickness, specifically designed to conform to the anatomy at the level of the bifurcation carina. A special version of the AXXESS System has been designed for left main bifurcation lesions, allowing for larger diameters (up to 4.75 mm) and distinct bifurcation angles (flare-end diameters of 8, 10 and 12 mm). The AXXENT trial is the first study to evaluate the vascular response of the self-expanding biolimus-eluting AXXESS stent for the treatment of LMCA bifurcation lesions. It was designed to evaluate the safety and efficacy of the AXXESS biolimus-eluting stent for the treatment of LMCA bifurcation lesions, that showed good results in terms of stent thrombosis and TLR at 6 months follow-up. Technical modifications and stent innovations may further improve both the angiographic and clinical outcomes for patients with wide angle bifurcation disease treated by PCI. Moreover a long term follow-up is needful to demonstrate better safety and efficacy of these new dedicated bifurcation devices.

Early, intermediate and late infectious complications after transcatheter or surgical aortic-valve replacement: a prospective cohort study.

Transcatheter aortic valve implantation (TAVI) has been proposed to treat older surgical high-risk patients with severe symptomatic aortic stenosis. There are no data regarding short-term and long-term infectious complications in these patients. The objective of this study was to define the incidence, aetiology and outcome of early and late infectious complications following TAVI compared with patients >65 years old undergoing traditional surgical aortic replacement (SAR). This was a prospective observational study evaluating all consecutive patients who underwent TAVI or SAR. Follow up was performed up to 1 year after the procedure of valve implantation. Fifty-one patients underwent TAVI and were compared with 102 patients who underwent SAR. Compared with SAR patients, those who underwent TAVI had lower incidence of early post-operative (11.7% vs 26.4%, p 0.04), intermediate (5.9% vs 17.6%, p 0.01) and late (7.8% vs 11.7%, p 0.03) infections. Among SAR patients the most common infections were bloodstream infections, pneumonias, urinary tract infections and sternal wound infections. Patients who underwent TAVI had a longer survival without infection (358 days vs 312.9, p 0.006). There were no significant differences in 12-month crude survival between the two study populations. Despite a high frequency of coexisting illnesses, patients undergoing TAVI develop few infectious complications. TAVI appears to be a reasonable and safe option in high-risk patients with severe symptomatic aortic stenosis.

Complete systolic obliteration of the left ventricle due to an apical hypertrophic cardiomyopathy in a totally asymptomatic patient.

A 30-years-old man, subjected to an electrocardiogram for screening, showed signs of left ventricular hypertrophy and "giant" inverted T-waves in pre-cordial leads. So, a transthoracic echocardiogram and a Coronary angiography were performed that showed first, a normal ventricular function and second, normal coronary arteries. Luckily, we associated to the Coronary angiography a Ventriculography that revealed a marked hypertrophy particularly in the apex and a 90% complete tele-systolic obliteration of the left ventricle. To better address our diagnosis, we performed a cardiac magnetic resonance that confirmed the Apical Hypertrophic Cardiomyopathy (AHCM) involving concentrically the apex known as "spade-like configuration" and an apical akinesia with slow-flow. Since the patient was totally asymptomatic, he was discharged without any treatment. AHCM is a form of Hypertrophic Cardiomyopathy (HCM) with an hypertrophy of the left ventricular apex. This disease is often sporadic and among the forms of HCM it has a benign prognosis although in > 50% of patients AHCM is symptomatic with chest pain and palpitations. Our patient incredibly never had cardiac symptoms and was always in a good health state, so only thanks to the association of Ventriculography to the Coronary angiography we were able to reach this unusual diagnosis.

Do angle and anatomy influence outcomes in bifurcation stenting?

Coronary bifurcation lesions are regarded as complex and their treatment is still the subject of substantial debate. Important elements to consider before approaching a bifurcation include angle and anatomy, in particular the take off angle (proximal angle, A) that is between the proximal MB and SB and the carina angle (distal angle, B) that is between distal main branch (MB) and side branch (SB) and also the extent and distribution of disease on the side branch and its size. Many techniques have been used to treat coronary bifurcation lesions such as provisional stenting or double stenting but no consensus technique has been accepted primarily due to variation of disease severity, angle and anatomy. Angle B is the unique statistically significant independent predictor factor influencing outcomes. Bifurcation angle and anatomy are important predictors of short and long-term outcomes after bifurcation treatment. Moreover we should evaluate it after wiring MB and SB so as after pre-dilatation because of side branch access and carina area angle anatomy variation and plaque shift. Should be investigated if the developing of new dedicated devices for bifurcation lesions could mix the advantages of one and two-stent techniques.

Global and regional longitudinal strain assessed by two-dimensional speckle tracking echocardiography identifies early myocardial dysfunction and transmural extent of myocardial scar in patients with acute ST elevation myocardial infarction and relatively preserved LV function.

AIMS: Global and regional longitudinal strain (GLS-RLS) assessed by two-dimensional speckle tracking echocardiography (2D-STE) are considered reliable indexes of left-ventricular (LV) function and myocardial viability in chronic ischaemic patients when compared with delayed-enhanced cardiac magnetic resonance (DE-CMR). In the present study, we tested whether GLS and RLS could also identify early myocardial dysfunction and transmural extent of myocardial scar in patients with acute ST elevation myocardial infarction (STEMI) and relatively preserved LV function. METHODS AND RESULTS: Twenty STEMI patients with LVEF ≥40%, treated with PPCI within 6 h from symptoms onset, underwent DE-CMR and 2D-echocardiography for 2D-STE analysis 6 ± 2 days after STEMI. Wall motion score index (WMSI) and LV ejection fraction (LVEF) were calculated by both methods. Infarct size and transmural extent of necrosis were assessed by CMR. GLS and RLS were obtained by 2D-STE. Mean GLS of the study population was -14 ± 3.3, showing a significant correlation with both LVEF and WMSI, by CMR (r = -0.86, P = 0.001, and r = 0.80, P = 0.001, respectively) and time-to-PCI (r = 0.66, P = 0.038). A weaker correlation was found between GLS and LVEF and WMSI assessed by 2D-echo (r = -0.65, P = 0.001, and r = 0.53, P = 0.013, respectively). RLS was significantly lower in DE-segments when compared with normal myocardium (P < 0.0001). A cut-off value of RLS of -12.3% by receiver-operating characteristic (ROC) curves identified DE-segments (sensitivity 82%, specificity 78%), whereas a cut-off value of -11.5% identified transmural extent of DE (sensitivity 75%, specificity 78%). CONCLUSION: Our findings indicate that RLS and GLS evaluation provides an accurate assessment of global myocardial function and of the presence of segments with transmural extent of necrosis, with several potential clinical implications.

Effect of coronary percutaneous revascularization on interferon-gamma and interleukin-10 producing CD4+ T cells during acute myocardial infarction.

T lymphocytes play an important role in the induction and progression of acute coronary syndromes (ACS). To gain insight into how different T cell subsets can influence ACS, we analyzed the frequencies of circulating CD4+ T cells producing either pro-inflammatory interferon(IFN)-gamma or anti-inflammatory interleukin (IL)-10 in subjects presenting with ST-elevation myocardial infarction (STEMI). The effect of coronary bare metal (BS) and paclitaxel-eluting stent (PES) on the balance between CD4+IFN-gamma+ and CD4+IL-10+ lymphocytes was also investigated. Peripheral blood mononuclear cells (PBMC) were isolated from 38 consecutive patients with STEMI before and 48 hrs or 6 days after implantation of either BS or PES. Twenty patients with no history of coronary artery disease were included as basal controls. PBMC were stimulated in vitro with anti-CD3/anti-CD28 monoclonal antibodies, and CD4+IFN- gamma+ or CD4+IL-10+ T cells were detected by flow cytometry intracellular staining. The frequency of peripheral CD4+IL-10+ T cells was significantly higher in STEMI patients as compared with controls. Conversely, the frequency of CD4+IFN-gamma+ T lymphocytes did not differ between STEMI and subjects without history of coronary artery disease. Six days after the revascularization procedure, the percentage of CD4+IL-10+ T cells was significantly decreased in BS but not in the PES group, whereas the relative percentage of CD4+IFN-gamma+ T lymphocytes were diminished in both groups as compared with baseline levels. Our data indicate that STEMI is associated with a peripheral expansion of CD4+IL-10+ T lymphocytes, and that primary coronary revascularization with implantation of either BS or PES is followed by a reduction in circulating CD4+IFN-gamma+ T lymphocytes. PES implantation, however, appears to inhibit the relative decrease of the IL-10 producing lymphocyte as observed in BS implanted patients, shifting the balance between pro-inflammatory and anti-inflammatory T cell populations in favor of the latter.

Impact of intracoronary aspiration thrombectomy during primary angioplasty on left ventricular remodelling in patients with anterior ST elevation myocardial infarction.

OBJECTIVE: To evaluate prospectively the impact on left ventricular (LV) remodelling of an intracoronary aspiration thrombectomy device as adjunctive therapy in primary percutaneous coronary intervention (PCI) in patients with anterior ST elevation myocardial infarction (STEMI). METHODS: 76 consecutive patients with anterior STEMI (65.3 (11.2) years, 48 men) were randomly assigned to intracoronary thrombectomy and stent placement (n = 38) or to conventional stenting (n = 38) of the infarct related artery. Each patient underwent transthoracic echocardiography immediately after PCI and at six months. At the time of echocardiographic control, major adverse cardiovascular events (MACE) in terms of death, new onset of myocardial infarction, and hospitalisation for heart failure were also evaluated. RESULTS: After a successful primary PCI, patients in the thrombectomy group achieved a higher rate of post-procedure myocardial blush grade 3 (36.8% v 13.1%, p = 0.03) and effective ST segment resolution at 90 minutes (81.6% v 55.3%, p = 0.02). Six months after the index intervention, 19 patients (26.8%) developed LV dilatation, defined as an increase in end diastolic volume (EDV) >or= 20%: 15 in the conventional group and four in the thrombectomy group (p = 0.006). Accordingly, at six months patients treated conventionally had significantly higher end systolic volumes (82 (7.7) ml v 75.3 (4.9) ml, p < 0.0001) and EDV (152.5 (18.1) ml v 138.1 (10.7) ml, p < 0.0001) than patients treated with thrombectomy. No differences in cumulative MACE were observed (10.5% in the conventional group v 8.6% in the thrombectomy group, not significant). CONCLUSION: Compared with conventional stenting, adjunctive aspiration thrombectomy in successful primary PCI seems to be associated with a significantly lower incidence of LV remodelling at six months in patients with anterior STEMI.

Effects of rotational atherectomy with a reduced burr-to-artery ratio on coronary no-reflow.

AIM: The use of rotational atherectomy in addition to standard percutaneous coronary interventional procedures, although it improves coronary blood flow dynamics by improving vessel geometry, is often associated with distal embolization and the no-reflow phenomenon. We sought to evaluate the safety and effectiveness of a burr size/reference artery diameter (RAD) ratio <0.7 in rotational atherectomy in order to reduce the distal embolization and then to analyze the procedural and peri-procedural no-reflow phenomenon. METHODS: Between March 1999 and May 2003, 50 consecutive patients with a chronic stable angina lasting more than 3 months underwent rotablator atherectomy, adjunctive stent im-plantation (primary coronary stenting, PCS) or plain old balloon angioplasty (POBA) in case of de novo lesions or in stent restenosis, respectively. We analyzed the target vessel myocardial blush grade and the troponin I, creatine kinase and CK-MB values at 1.6 and every 8 h during the first day and then daily until discharge. RESULTS: Procedural success was achieved in all 50 patients (mean age 55+/-11 years; 45 males, 5 females). Quantitative angiography revealed, in the group treated with PCS, an increase in minimal lumen diameter (MLD) from 0.88+/-0.39 mm at baseline to 1.4+/-0.63 mm after rotablator (p<0.01) to 2.85+/-0.9 mm after stent implantation (p<0.01). On the other hand, for the group treated with POBA, the MLD changed from 1.8+/-0.32 mm at baseline to 2.2+/-0.54 mm after rotablator (p=0.6) to 3.28+/-0.91 mm after adjunctive balloon angioplasty (p<0.01). No statistically significant changes have been observed between myocardial blush grade and enzymes between baseline and after the procedure. CONCLUSION: Rotablator atherectomy with a reduced burr size/RAD ratio is a safe and effective interventional procedure without any peri-procedural no-reflow phenomenon.

Integrin beta2-chain (CD18) over-expression on CD4+ T cells and monocytes after ischemia/reperfusion in patients undergoing primary percutaneous revascularization.

beta2-integrin subunit (CD18) plays an essential role in leukocyte recruitment and adhesion in sites of endothelial injury. We analyzed the surface expression of CD18 on T lymphocytes and monocytes in a series of patients presenting acute coronary syndrome (ACS) who underwent primary percutaneous intervention (PCI) for coronary artery revascularization. We found that basal CD18 expression on peripheral blood-derived CD4+ (but not CD8+) T lymphocytes was significantly increased in ACS patients as compared with age-matched healthy volunteers. During primary PCI, a significant increase in CD18 molecule density was detected immediately after balloon deflation (reperfusion) on both CD4+ T cells and monocytes obtained from the right atrium (RT) as compared with basal values. These data suggest that upregulation of CD18 molecules plays an important role in local recruitment of CD4+ T cells and monocytes to the site of endothelial damage after ischemia/reperfusion, therefore being responsible, at least in part, for the inflammatory-mediated complications associated with primary PCI.

Assessment of flow velocity reserve by transthoracic Doppler echocardiography and venous adenosine infusion before and after left anterior descending coronary artery stenting.

OBJECTIVES: We sought to evaluate whether coronary flow velocity reserve (CFR) (the ratio between hyperemic and baseline peak flow velocity), as measured by transthoracic Doppler echocardiography during adenosine infusion, allows detection of flow changes in the left anterior descending coronary artery (LAD) before and after stenting. BACKGROUND: The immediate post-stenting evaluation of CFR by intracoronary Doppler has shown mixed results, due to reactive hyperemia and microvascular stunning. Noninvasive coronary Doppler echocardiography may be a more reliable measure than intracoronary Doppler. METHODS: Transthoracic Doppler echocardiography during 90-s venous adenosine infusion (140 microg/kg body weight per min) was used to measure CFR of the LAD in 45 patients before and 3.7 +/- 2 days after successful stenting, as well as in 25 subjects with an angiographically normal LAD (control group). RESULTS: Adequate Doppler spectra were obtained in 96% of the patients. Pre-stent CFR was significantly lower in patients than in control subjects (diastolic CFR: 1.45 +/- 0.5 vs. 2.72 +/- 0.71, p < 0.01; systolic CFR: 1.61 +/- 1.02 vs. 2.41 +/- 0.68, p < 0.01) and increased toward the normal range after stenting (diastolic CFR: 2.58 +/- 0.7 vs. 2.72 +/- 0.75, p = NS; systolic CFR: 2.43 +/- 1.01 vs. 2.41 +/- 0.52, p = NS). Diastolic CFR was often damped, suggesting coronary steal in patients with > or =90% versus <90% LAD stenosis (0.86 +/- 0.23 vs. 1.69 +/- 0.43, p < 0.01). Coronary stenting normalized diastolic CFR in these two groups (2.45 +/- 0.77 and 2.64 +/- 0.69, respectively, p = NS), even though impaired diastolic CFR persisted in three of four patients with > or =90% stenosis. Stenosis of the LAD was better discriminated by diastolic (F = 49.30) than systolic (F = 12.20) CFR (both p < 0.01). CONCLUSIONS: Coronary flow reserve, as measured by transthoracic Doppler echocardiography, is impaired in LAD disease; it may identify patients with > or =90% stenosis; and it normalizes early after stenting, even in patients with > or =90% stenosis.

Rheumatic fever recurrence: a possible cause of restenosis after percutaneous mitral valvuloplasty.

BACKGROUND: We evaluated the occurrence of a rapid process of restenosis after percutaneous mitral valvuloplasty (PMV), initiated by the recurrence of acute rheumatic fever. Restenosis after PMV has been mainly related to a high echocardiographic score (> or = 8) indicating a severely compromised mitral valve apparatus. METHODS: From 1986 to 1996, 120 patients underwent PMV by the transseptal approach at our Institution. The mean follow-up time was 58 +/- 32 months (range 3 months to 9 years). RESULTS: Restenosis occurred in 10 patients (8.3%): in 4 restenosis was found within a relatively short period of time (1 to 3 months) following a documented recurrence of acute rheumatic fever; in the other 6 patients there was a gradual loss of the initial gain in the mitral valve area. CONCLUSIONS: These data suggest two potential mechanisms of restenosis: 1) a more common slow process, due to turbulent flow-trauma on the mitral valve; 2) a rapid process that relates to valvulitis consequent to a recurrence of acute rheumatic fever. In consideration of the second possibility, after PMV prophylactic treatment may be warranted at least in those patients who are at high risk of streptococcal infection.

Non-invasive assessment of coronary flow velocity reserve before and after angioplasty in a patient with mammary graft stenosis.

We report the diagnosis of mammary artery graft dysfunction by high-resolution transthoracic Doppler and venous adenosine infusion. The patient was treated by percutaneous balloon angioplasty, with optimal angiographic results. Coronary flow reserve in the distal left anterior descending artery was abnormal before angioplasty, and recovered soon after the procedure. The utility of this new non-invasive technique in the diagnosis of flow-limiting stenoses and follow-up of coronary angioplasty is described.

Role of sex hormones in development of chronic mountain sickness in rats.

After chronic exposure to hypoxia, Hilltop Sprague-Dawley rats developed excessive polycythemia and severe pulmonary hypertension and right ventricular (RV) hypertrophy, signs consistent with human chronic mountain sickness; however, there were gender differences in the magnitude of the polycythemia and susceptibility to the fatal consequence of chronic mountain sickness. Orchiectomy and ovariectomy were performed to evaluate the role of sex hormones in the gender differences in these hypoxic responses. After 40 days of exposure to simulated high altitude (5,500 m; barometric pressure of 370 Torr and inspired Po2 of 73 Torr), both sham-gonadectomized male and female rats developed polycythemia and had increased RV peak systolic pressure and RV hypertrophy. The hematocrit was slightly but significantly higher in males than in females. Orchiectomy did not affect these hypoxic responses, although total ventricular weight was less in the castrated high-altitude rats. At high altitude, the mortality rates were 67% in the sham-operated male rats and 50% in the castrated animals. In contrast, ovariectomy aggravated the high-altitude-associated polycythemia and increased RV peak systolic pressure and RV weight compared with the sham-operated high-altitude female rats. Both sham-operated control and ovariectomized females suffered negligible mortality at high altitude. The present study demonstrated that 1) the male sex hormones play no role in the development of the excessive polycythemia, pulmonary hypertension, and RV hypertrophy during chronic hypoxic exposure or in the associated high mortality and 2) the female sex hormones suppressed both the polycythemic and cardiopulmonary responses in vivo during chronic hypoxic exposure.

[The acute and 24-hour modifications to the atrial natriuretic factor in patients who have undergone mitral valvuloplasty. The hemodynamic and echocardiographic correlations]. / Modificazioni acute ed a 24 ore del fattore natriuretico atriale in pazienti sottoposti a valvuloplastica mitralica. Correlazioni emodinamiche ed ecocardiografiche.

BACKGROUND: The recent introduction of percutaneous transvenous mitral valvuloplasty (PTMV) for the treatment of mitral stenosis (MS) has provided a unique human model for the study of short-term changes in ANF secretion before and after a reduction in left atrial pressure. This study was designed to investigate the effect of a short-term reduction in left atrial pressure and volume, as determined by echocardiographic study, on ANF and other neurohumoral factor plasma levels (renin and aldosterone). MATERIALS AND METHODS: 10 patients in III FC NYHA, with normal sinus rhythm and MS underwent PTMV. Hemodynamic parameters were measured immediately before and after (20-30 minutes) PTMV. Plasma levels of ANF, aldosterone and plasma renin activity (PRA) were obtained before (24 h) and after (2 h and 24 h) valvuloplasty; echocardiographic left atrial size before (24 h) and 24 h after PTMV. RESULTS: Immediately after PTMV mean left atrial (LA) pressure decreased from 22.3 +/- 6.8 mmHg to 10.0 +/- 2.4 mmHg (p < 0.01); mitral valve area (MVA) increased from 0.99 +/- 0.28 cm2 to 2.17 +/- 0.26 cm2 (p < 0.01). 24 hours after PTMV on echocardiography, LA systolic volume decreased from 59.5 +/- 16.9 cm3 to 42.3 +/- 8.3 cm3 (p < 0.01), LA diastolic volume from 82.6 +/- 15.8 cm3 to 66.5 +/- 12.6 cm3 (p < 0.01), and LA diameter from 48.1 +/- 7.5 mm to 39.2 +/- 4.4 mm (p < 0.01). ANF plasma levels before PTMV were 64.0 +/- 36.9 fmol/ml; 2 and 24 hours after PTMV they fell to 34.2 +/- 21.6 fmol/ml (p < 0.01) and to 20.3 +/- 21.0 fmol/ml (p < 0.01), respectively. PRA values were 15.7 +/- 13.2 ng/ml/h before PTMV; 2 and 24 hours after PTMV they increased to 17.5 +/- 23.2 ng/ml/h (NS) and to 22.3 +/- 16.8 ng/ml/h (p < 0.01). The aldosterone plasma levels were 43.2 +/- 27.9 ng/dl before PTMV and 47.3 +/- 35.8 ng/dl (NS) and 45.3 +/- 28.0 ng/dl (NS) 2 and 24 hours after PTMV. CONCLUSIONS: These results indicate that LA "de-stretching" due to the MVA increase and LA pressure decrease, leads to an abrupt reduction of ANF secretion. According to other studies, PRA increases immediately after PTMV, with a further increase 24 hours after PTMV.

Possible role of pulmonary blood volume in chronic hypoxic pulmonary hypertension.

Chronic hypoxia increases the total blood volume (TBV) and pulmonary arterial blood pressure (Ppa) and induces pulmonary vascular remodeling. The present study was undertaken to assess how the pulmonary blood volume (PBV) changes during hypoxia and the possible role of PBV in chronic hypoxic pulmonary hypertension. A novel method has been developed to measure the TBV, PBV, and Ppa in conscious rats. The method consists of chronic implantation of a loose ligature around the ascending aorta and pulmonary artery, so that when the ligature is drawn tightly, it traps the blood in the pulmonary vessels and left heart and simultaneously kills the rat. The pulmonary veins are then ligated to separate the left ventricular blood volume from the PBV. This surgical approach, together with chronic catheterization of the pulmonary artery and the use of 51Cr-labeled red blood cells, allows measurement of TBV, PBV, and Ppa. This method has been used to analyze the relationships between TBV and PBV and between Ppa or right ventricular hypertrophy and PBV in two rat strains with markedly different TBV and Ppa responses to chronic hypoxia. PBV per given lung weight did not increase and even decreased during hypoxia despite marked increases in TBV. There was a close correlation between Ppa or right ventricular hypertrophy and PBV in the two strains of chronically hypoxic animals, suggesting that a greater PBV plays a significant role in the development of severe chronic hypoxic pulmonary hypertension in the altitude-susceptible Hilltop rats.