Multivariate Cox Proportional-hazards Regression Analysis Research Articles

Coexpression of hypoxia-inducible factor-1α and glucose transporter-1 is associated with poor prognosis in oral squamous cell carcinoma patients

To study whether coexpression of the two hypoxia-related proteins hypoxia-inducible factor (HIF)-1α and glucose transporter (GLUT)-1 has prognostic relevance in oral squamous cell carcinomas (OSCCs). Eighty-two OSCC samples were analysed for expression levels of HIF-1α and GLUT-1 by immunohistochemistry. Protein expression was assessed with an immunoreactive score system, and the correlations between gene expression and both clinical and pathohistological parameters were examined. Overexpression of either GLUT-1 or HIF-1α was associated with poor disease-specific survival in OSCC patients. Multivariate Cox proportional-hazards regression analysis revealed that increased expression of HIF-1α was significantly associated with disease-specific survival (relative risk = 3.24, P = 0.024), as compared with the group with a low level of expression. Coexpression of HIF-1α and GLUT-1 was additively and significantly associated with adverse prognoses in patients with OSCC. Patients whose tumours had increased levels of expression of both HIF-1α and GLUT-1 were found to have a 5.13-fold increased risk of tumour-related death (P = 0.017). Coexpression of high levels of HIF-1α and GLUT-1 is significantly correlated with prognosis in OSCC patients, suggesting that the coexpression of these proteins can be used as both an early diagnostic and independent prognostic marker.

Statin Treatment for Patients With Paroxysmal Atrial Fibrillation A J-RHYTHM Substudy

Recent clinical evidence and animal experiments support the belief that statins have beneficial effects on cardiovascular outcomes and prevention of atrial fibrillation (AF). We investigated whether the use of statins reduces the mortality, morbidity, and recurrence rate of AF in patients with paroxysmal AF. A post hoc analysis of the Japanese Rhythm Management Trial for Atrial Fibrillation (J-RHYTHM) study was conducted.Of the 823 patients with paroxysmal AF in the J-RHYTHM study, 101 (12.3%) were receiving a statin at baseline. Patients taking statins were older and more likely to have hypertension, dyslipidemia, coronary artery disease, and ischemic stroke compared to patients not taking statins. During a mean follow-up period of 19.3 months, 40 patients (5.5%) reached the primary endpoint (a composite of all-cause death, stroke, systemic embolism, major bleeding, and hospitalization for heart failure) and 140 patients (19.4%) experienced a recurrence of AF. Multivariate Cox proportional-hazard regression analysis revealed statin use was not associated with improved mortality and morbidity (hazard ratio [HR] 0.409, 95% confidence interval [CI] 0.113-1.482), or a decreased risk of AF recurrence (HR 0.662, 95% CI 0.299-1.466).This analysis provides evidence that statin use did not affect clinical outcomes in patients with paroxysmal AF and emphasizes the need for randomized clinical trials defining more clearly the role of statins in treating AF.

Predictors of Outcome of Mitral Valve Prolapse in Patients With the Marfan Syndrome

Mitral valve prolapse has a prevalence of 2% to 3% in the general population, with adverse outcomes such as mitral valve regurgitation (MVR), heart failure, and endocarditis. Predictors of outcomes are used in idiopathic mitral valve prolapse for the timing of surgery, but such predictors are unknown in Marfan syndrome. Therefore, a population-based cohort study of 112 patients (49 male, 63 female; mean age 34 ± 15 years) with classic Marfan syndrome and mitral valve prolapse with moderate or less MVR at baseline was conducted. During 4.6 ± 3.6 years of follow-up, progression of MVR was observed in 41 patients and valve-related events, which comprised mitral valve endocarditis (7 events), heart failure (5 events), and mitral valve surgery (25 events), were observed in 31 patients. Multivariate Cox proportional-hazards regression analysis identified a flail mitral leaflet (hazard ratio [HR] 3.262, 95% confidence interval [CI] 1.406 to 7.566, p = 0.006) and increased indexed end-systolic left ventricular diameters (HR 1.113, 95% CI 1.043 to 1.188, p = 0.001) as independent predictors of progression of MVR. Similarly, mitral valve-related events were independently predicted by a flail mitral leaflet (HR 5.343, 95% CI 2.229 to 12.808, p <0.001), and mild (HR 14.336, 95% CI 1.873 to 109.755, p = 0.01) or moderate (HR 16.849, 95% CI 2.205 to 128.76, p = 0.006) degree of MVR. Conversely, aortic dilatation, dural ectasia, and sporadic mode of inheritance were not associated with outcome. In conclusion, the same clinical determinants that predict outcomes in idiopathic mitral valve prolapse also predict outcomes in mitral valve prolapse associated with Marfan syndrome.

Risk Stratification of Non-Ischemic Heart Failure Using Simplified Selvester QRS Scoring System

Objectives:Multiple studies have shown that simplified Selvester QRS scoring system (SSS) can estimate the myocardial infarct size, left ventricular function and is predictive of mortality. We then examined the relation of the SSS for the estimation of mortality in non-ischemic heart failure.Methods:We studied 136 consecutive patients (age, 72.1±13.7 years, 73 males, left ventricular ejection fraction 38.6±16.1%) who were admitted to our hospital for the treatment of worsening heart failure between January 2008 and January 2009. The absence of coronary artery disease was confirmed by radionuclide scintigraphy, computed tomography, or coronary angiography. The Selverster QRS score was determined using the 12-lead ECG at discharge by two cardiologists who were blinded to the clinical outcome. The primary endpoint was a composite of all-cause death or hospitalization for heart failure.Results:During a mean follow-up period of 11 months, 73 (54%) patients met the primary endpoint. Higher QRS scores were associated with lower survival rates. The multivariate Cox proportional-hazard regression analysis revealed that QRS score provide independent information on the mortality (hazard ratio 1.07, 95% confidence interval 1.07 to 1.12: p=0.009).Conclusions:The SSS can be a useful clinical tool for risk stratification in heart failure patients with non-ischemic origin.

A retrospective cohort study of prognostic factors for death in patients with idiopathic pulmonary fibrosis

To investigate the prognostic implications of clinical, radiographic, and physiological variables in idiopathic pulmonary fibrosis (IPF). The clinical, pulmonary physiological, bronchoalveolar lavage fluid (BALF) cell differentials and lung high-resolution computed tomography (HRCT) at diagnosis in 126 patients with IPF were retrospectively analyzed. Univariate and multivariate Cox proportional-hazards regression analysis was used to evaluate various parameters associated with hazard ratio (HR). The survival rates of all groups were compared using the Kaplan-Meier method. In 29.6 months of average follow-up time, the survival rate of the IPF patients was 46.8% (59/126), and the median survival time was 30 months after diagnosis. Glucocorticoids and/or cytotoxic drugs for patients with IPF did not change the prognosis. The survival rates between groups by gender and smoking status showed no statistically significant difference (Ward: 0.11, 1.65, P>0.05). The patients were divided into 2 groups by the median (the cutoff point value) of significant variables in univariate Cox proportional-hazards regression analysis, and the survival rates showed statistically significant difference by dyspnea scale, FVC%, TLC%, DLCO%, neutrophil percentage and eosinophil percentage in BALF, and the reticular and honeycomb lung score (Logrank: 13.52-57.52, P<0.05). The results of multivariate Cox proportional-hazards regression analysis showed that TLC%, DLCO%, HRCT reticular score and honeycomb lung score were factors that affected the prognosis of patients with IPF (Wald=5.76-21.48, P<0.05). TLC%, DLCO%, cell differentials of BALF and the degree of pulmonary fibrosis were the main factors affecting the prognosis of patients with IPF. TLC% and DLCO% showed a negative correlation with the prognosis of patients with IPF. Glucocorticoids and/or cytotoxic drug therapy had no effect on the prognosis of patients with IPF.

Fatty Acid Amide Hydrolase in Prostate Cancer: Association with Disease Severity and Outcome, CB1 Receptor Expression and Regulation by IL-4

BackgroundRecent data have indicated that there may be a dysregulation of endocannabinoid metabolism in cancer. Here we have investigated the expression of the endocannabinoid metabolising enzyme fatty acid amide hydrolase (FAAH) in a well characterised tissue microarray from patients diagnosed with prostate cancer at transurethral resection for voiding problems.Methodology/Principal FindingsFAAH immunoreactivity (FAAH-IR) was assessed in formalin-fixed paraffin-embedded non-malignant and tumour cores from 412 patients with prostate cancer. CB1 receptor immunoreactivity (CB1IR) scores were available for this dataset. FAAH-IR was seen in epithelial cells and blood vessel walls but not in the stroma. Tumour epithelial FAAH-IR was positively correlated with the disease severity at diagnosis (Gleason score, tumour stage, % of the specimen that contained tumour) for cases with mid-range CB1IR scores, but not for those with high CB1IR scores. For the 281 cases who only received palliative therapy at the end stages of the disease, a high tumour epithelial FAAH-IR was associated with a poor disease-specific survival. Multivariate Cox proportional-hazards regression analyses indicated that FAAH-IR gave additional prognostic information to that provided by CB1IR when a midrange, but not a high CB1IR cutoff value was used. Interleukin-4 (IL-4) receptor IR was found on tumour epithelial cells and incubation of prostate cancer PC-3 and R3327 AT1 cells with IL-4 increased their FAAH activity.Conclusions/SignificanceTumour epithelial FAAH-IR is associated with prostate cancer severity and outcome at mid-range, but not high, CB1IR scores. The correlation with CB1IR in the tumour tissue may be related to a common local dysregulation by a component of the tumour microenvironment.

Prognostic value of established and novel biomarkers in patients with shortness of breath attending an emergency department

ObjectivesAcute dyspnea is a common cause for emergency department visits. The aim of this study was to evaluate the prognostic value of established and novel biomarkers in patients with acute dyspnea. Design and methodsWe measured 10 biomarkers [B-type natriuretic peptide (BNP), midregional pro-A-type natriuretic peptide (MR-proANP), midregional-proadrenomedullin (MR-proADM), copeptin, C-terminal endothelin-1 precursor fragment (CT-proET-1), soluble ST2 (sST2), chromogranin A (CgA), adiponectin, proguanylin, and prouroguanylin] in 251 consecutive patients with acute dyspnea presenting to the emergency department of a tertiary care hospital. Outcome measure was all-cause mortality at 1 year. ResultsAt baseline decedents (n=62) had significantly higher median plasma concentrations of all 10 biomarkers than survivors (n=189). Applying univariate Cox proportional-hazard regression analyses, all biomarkers were significant outcome predictors displaying risk ratios (RR) from 1.4 to 2.4 (per 1 SD increase in log transformed values). In multivariate Cox proportional-hazard regression analysis, however, only MR-proANP (RR 1.6; 95% CI, 1.1–2.2; p=0.008), sST2 (RR 1.7; 95% CI, 1.3–2.3; p<0.001), and CgA (RR 1.5; 95% CI, 1.2–1.9, p<0.001) were independently associated with 1-year mortality. We provide a possible explanation for the complementary prognostic value of those three biomarkers in our cohort, where coincidence of heart failure and inflammatory pulmonary disease was common and also related to worse outcome. ConclusionsOur evaluation of biomarkers in patients with acute dyspnea suggests that MR-proANP, sST2, and CgA are strong, independent and complementary outcome predictors. MR-proANP is considered a specific marker of cardiac stretch, sST2 might reflect both inflammation and cardiac stretch, and CgA obviously indicates neuroendocrine activation in various diseases.

Infrapopliteal Application of Sirolimus-eluting versus Bare Metal Stents for Critical Limb Ischemia: Analysis of Long-term Angiographic and Clinical Outcome

To present the 3-year angiographic and clinical results of a prospective registry investigating the performance of sirolimus-eluting stents (SESs) versus bare metal stents (BMSs) for critical limb ischemia (CLI) treatment. A single-center double-arm prospective registry included patients with CLI who underwent infrapopliteal revascularization with angioplasty and "bailout" use of an SES or BMS. Clinical and angiographic follow-up was scheduled at regular time intervals. Primary clinical and angiographic endpoints included mortality, limb salvage, primary patency, binary angiographic restenosis (ie, >50%), and clinically driven repeat intervention-free survival. Results were stratified according to stent type, and cumulative proportion outcomes were determined by Kaplan-Meier plots. Multivariable Cox proportional-hazards regression analysis was applied to adjust for confounding factors of heterogeneity. In total, 103 patients were included in the analysis; 41 (75.6% with diabetes) were treated with a BMS (47 limbs; 77 lesions) and 62 (87.1% with diabetes) with an SES (75 limbs; 153 lesions). At 3 years, SES-treated lesions were associated with significantly better primary patency (hazard ratio [HR], 4.81; 95% CI, 2.91-7.94; P < .001), reduced binary restenosis (HR, 0.38; 95% CI, 0.25-0.58; P < .001), and better repeat intervention-free survival (HR, 2.56; 95% CI, 1.30-5.00; P = .006) versus BMS-treated ones. No significant differences were identified between SESs and BMSs with regard to overall 3-year patient mortality (29.3% vs 32.0%; P = .205) and limb salvage (80.3% vs 82.0%; P = .507). Infrapopliteal application of SESs for CLI significantly improves angiographic long-term patency and reduces infrapopliteal vascular restenosis versus BMSs, thereby lessening the rate of clinically driven repeat interventions.

The association between extent of lymphadenectomy and survival among patients with lymph node metastases undergoing radical cystectomy

Long-term survival in patients with lymph node-positive bladder cancer who undergo cystectomy suggests a therapeutic role for lymphadenectomy. The objective of this study was to describe the association between extent of lymphadenectomy and survival in lymph node-positive patients who underwent radical cystectomy. The cohort consisted of patients from the Surveillance, Epidemiology, and End Results registry with transitional cell carcinoma who underwent cystectomy with lymphadenectomy and had at least 1 positive lymph node and no distant metastases. The Kaplan-Meier method and multivariate Cox proportional-hazards regression analyses were used to estimate differences in survival among different lymphadenectomy variables. In total, 1260 patients had at least 1 positive lymph node. A median of 9 lymph nodes were removed (range, 1-48 lymph nodes) with a median of 2 positive lymph nodes (range, 1-18 positive lymph nodes), and the median lymph node density was 22%. In multivariate analysis controlling for patient demographics, tumor classification, and year of diagnosis, the number of positive and total lymph nodes removed remained independent predictors of survival. There was an inverse association between the number of lymph nodes removed and the risk of death for all quartiles. Removal of > 10 lymph nodes was associated with increased overall survival (hazard ratio, 0.52; 95% confidence interval, 0.43-0.64). In addition, with a lymph node density from 0.1% to 12.5% as the referent group, each higher quartile experienced worse survival. An increased number of lymph nodes removed at the time of cystectomy was associated with improved survival in patients with lymph node-positive bladder cancer. Improved survival was observed at a lower lymph node density threshold than previously reported. The current findings support performing a more extensive lymphadenectomy at the time of cystectomy.

Oncological efficacy and safety of nephron‐sparing surgery for selected patients with locally advanced renal cell carcinoma

To evaluate perioperative complication rates, recurrence-free and cancer-specific survival (CSS) in a large group of matched patients who had nephron-sparing surgery (NSS) or radical nephrectomy (RN) for pT2-T3bN0M0 renal cell carcinoma (RCC). With approval from the institutional review board, the institutional nephrectomy database of 3470 patients treated at the authors' institution from 1990 to 2006 was searched for patients who had NSS or RN for unilateral, sporadic, pathological T2-T3bN0M0 RCC. Patients with non-metastatic, node-negative RCC and a follow-up of >/=6 months were included in the analysis. In all, 601 patients treated with RN (567) or NSS (34) for pT2-T3bN0M0 RCC and a mean (median, range) follow-up of 43.4 (31.8, 6.1-172.6) and 62.1 (37.5, 7.0-192.0) months, respectively, met the study inclusion criteria. Disease recurred in four of 34 (12%) patients treated with NSS and in 164/567 (28.9%) managed with RN at a median of 24.2 and 13.2 months, respectively. There were no local recurrences among patients treated with NSS. On multivariate Cox proportional-hazards regression analysis, when adjusted for the effects of stage, grade, size and tumour histology, procedure type (NSS vs RN) was not an independent predictor of disease recurrence or RCC-specific death. Patients treated with NSS had a higher procedure-related complication rate, but similar estimated intraoperative blood loss, transfusion rate, equal duration of surgical procedure and hospital stay compared with patients managed with RN. In highly selected patients with locally advanced RCC, NSS is safe and provides oncological outcomes equivalent to patients managed with RN.

Clinical Outcome of Thrombotic Microangiopathy after Living-Donor Liver Transplantation Treated with Plasma Exchange Therapy

Thrombotic microangiopathy (TMA) is a well-documented but severe complication that occurs after solid-organ transplant. Administration of calcineurin inhibitors is considered a major cause of this fatal complication; prompt initiation of plasma exchange therapy after reduction or conversion of calcineurin inhibitors has been recommended. Nevertheless, little is known about clinical evidence of this strategy against TMA after solid-organ, especially non-renal-organ, transplantation. Medical records of 63 patients who were hospitalized at Artificial Organ and Transplantation Division in Tokyo University Hospital and underwent blood purification therapy between January 1999 and May 2005 were reviewed. Twenty-eight living-donor liver transplantation (LDLT) recipients who received plasma exchange therapy were identified, and 18 of them were found retrospectively to receive a diagnosis of having TMA. Of the 18 patients, 10 (56%) responded to this therapy and survived after the treatment was stopped, whereas eight (44%) patients died before improvement. Subsequent follow-up of patients clarified that 1-yr survival rate of post-LDLT TMA was approximately 30%. Multivariate Cox proportional-hazards regression analysis demonstrated that the interval between transplant surgery and onset of TMA (hazard ratio 1.35 per 30 d; 95% confidence interval 1.07 to 1.71; P = 0.021) and pretreatment blood urea nitrogen level (hazard ratio 1.39 per 10 mg/dl; 95% confidence interval 1.02 to 1.90; P = 0.037) predicted mortality. Analyses identified post-LDLT recipients with TMA as being at high risk for poor prognosis. Effective strategies are needed for late-onset TMA after LDLT to improve treatment response and survival.

B-type natriuretic peptide and amino terminal proBNP predict one-year mortality in short of breath patients independently of the baseline diagnosis of acute destabilized heart failure

Background The aim of the present study was to demonstrate the capability of B-type natriuretic peptide (BNP) and amino terminal proBNP (NT-proBNP) as prognostic markers in patients with dyspnoea as a chief complaint. Methods BNP and NT-proBNP plasma concentrations were obtained from 251 short of breath patients presenting to the emergency department of a tertiary care hospital. Patients with acute coronary syndromes or trauma were excluded. The endpoint was defined as all-cause mortality, and the study participants were followed up for 365 days from the time they attended the emergency department. Results Of the 251 patients, 62 died and 189 stayed alive during follow-up. In the present study, optimal cut off levels for the prediction of survival were 454 ng/L for BNP, and 2060 ng/L for NT-proBNP. Mortality was higher in patients with baseline BNP and NT-proBNP concentrations above these cut off levels (log rank p < 0.001; hazard ratios, 0.325 and 0.357, respectively). In multivariate Cox proportional-hazards regression analyses, elevated BNP/NT-proBNP, low systolic blood pressure, and renal dysfunction were predictors of mortality even when the baseline diagnosis of acute destabilized heart failure was factored into the model. Conclusions Both BNP and NT-proBNP measures obtained from short of breath patients presenting to an emergency department may be predictive of one-year all-cause mortality independently of the baseline diagnosis of acute destabilized heart failure.

Prognostic Impact of Plasma Brain Natriuretic Peptide for Cardiac Events in Elderly Patients with Congestive Heart Failure

Background: Plasma brain natriuretic peptide (BNP) has been reported to be useful in determining the prognosis of patients with ischemic heart disease and cardiomyopathy. However, aging increases the level of plasma BNP; therefore, the prognostic impact of plasma BNP in elderly patients with congestive heart failure has not been fully established. Objective: We sought to determine whether plasma BNP could predict recurrent cardiac events in elderly patients with congestive heart failure. Methods: Forty-eight consecutive elderly patients (>65 years old) were enrolled in the present study. All patients were admitted with their first episode of congestive heart failure. Clinical characteristics, plasma BNP, left ventricular ejection fraction, and left ventricular mass index were compared between patients with and those without recurrent cardiac events. Results: During the follow-up period, twelve cardiac events were observed. The New York Heart Association functional class was signi- ficantly higher in patients with cardiac events than in those without (p < 0.05). The plasma BNP level in pa- tients with cardiac events was significantly higher than in those without (521.0 ± 156.0 vs. 126.8 ± 20.1 pg/ml, p < 0.001), despite more frequent treatment with angiotensin-converting enzyme inhibitors (75 vs. 28%, p < 0.05). The left ventricular ejection fraction was significantly lower and the left ventricular mass index higher in patients with cardiac events as compared with those without (38.1 ± 5.0 vs. 49.2 ± 2.4%, p < 0.05; 193.8 ± 14.3 vs. 132.6 ± 7.8 g/m², p < 0.001, respectively). The plasma BNP was selected as an independent factor associated with cardiac events besides New York Heart Association functional class, left ventricular ejection fraction, and left ventricular mass index using multivariate Cox proportional-hazards regression analysis (hazard ratio = 2.656, p < 0.05). The cardiac event rate was significantly higher in patients with a plasma BNP concentration >132 pg/ml using Kaplan-Meier analysis (p < 0.001). Moreover, the plasma BNP level correlated inversely with the length of time from hospital discharge to a cardiac event (r = –0.575, p < 0.05). Conclusion: Measuring the plasma BNP level before hospital discharge in elderly patients with congestive heart failure was more useful than other conventional examinations for predicting the recurrence of cardiac events.

Usefulness of serum troponin T levels on day three or four in predicting survival after acute myocardial infarction

The appearance of serum troponin T (tn-T) on day 1 after acute myocardial infarction (AMI) strongly depends on coronary reperfusion. In contrast, the kinetics of tn-T release after day 1 after AMI are unaffected by the reperfusion status, and reflect the degradation of myofilaments in irreversibly damaged cells. However, it is not known whether serum tn-T levels after day 1 after AMI can be used to predict the long-term outcome. The purpose of this study was to elucidate the prognostic value of determining the tn-T level on day 3 or 4 after AMI. Serum tn-T levels on day 3 or 4 after AMI were measured in 121 patients (92 men and 29 women, mean age 65 years). Mean follow-up period was 526 days. There were 12 deaths (9 cardiac and 3 noncardiac) during the follow-up period. By Kaplan-Meier analysis, patients with tn-T levels higher than the median level (6.9 ng/ml) had a significantly higher mortality rate than those with submedian levels (p <0.01). By multivariate Cox proportional-hazards regression analysis, the serum tn-T level was an independent predictor of the long-term outcome after AMI (p <0.01). Futhermore, in patients with a first AMI, the serum tn-T level exhibited a significant negative linear correlation with left ventricular ejection fraction assessed 4 weeks after AMI (r = −0.48, p <0.001). Increased serum tn-T levels on day 3 or 4 after AMI are a powerful noninvasive predictor of poor long-term prognosis, reflecting residual left ventricular function after AMI.

Plasma concentration of brain natriuretic peptide as a biochemical marker for the evaluation of right ventricular overload and mortality in chronic respiratory disease

The purpose of this study was to evaluate whether the plasma brain natriuretic peptide (BNP) concentration is a useful marker of right ventricular (RV) overload and whether it has prognostic value as a predictor of death in patients with chronic respiratory disease (CRD). We measured the plasma BNP and atrial natriuretic peptide (ANP) concentrations in 31 consecutive patients with CRD who underwent right-heart catheterization to evaluate pulmonary hypertension. All patients were followed for >12 months. The plasma BNP concentration closely correlated with the mean pulmonary artery pressure and pulmonary vascular resistance ( r=0.62, P<0.0005 and r=0.85, P<0.0001), and showed a weak linear correlation with cardiac output ( r=−0.36, P<0.05). During the follow-up period, 5 (16%) end-stage CRD deaths (4 RV heart failure and 1 respiratory infection) and 2 non-end-stage CRD deaths occurred. In a stepwise multivariate Cox proportional-hazards regression analysis including age, sex, BNP, ANP, hemodynamic variables and the ratio of PaO 2 to fraction of inspired oxygen, only BNP ( P<0.05) was an independent predictor of end-stage CRD death. The upward and leftward shift in the receiver operating characteristic curve between patients with end-stage CRD death and those without was greater for BNP than for ANP. Our findings suggest that the plasma BNP concentration may be an inexpensive, simple and useful marker of RV overload and end-stage CRD death in CRD patients. These preliminary results need to be confirmed in a large series of CRD patients.

Survival in primary pulmonary hypertension. Validation of a prognostic equation.

The prognosis of patients with primary pulmonary hypertension (PPH) remains a major problem for the planning and assessment of therapeutic interventions. The objectives of this study were (1) to characterize mortality in a Mexican population of patients with PPH and to investigate factors associated with survival and (2) to test the applicability in this population of the prognostic equation proposed by the US National Institutes of Health study on PPH. A dynamic cohort of patients with PPH at our institution were enrolled between June 1977 and August 1991 and prospectively followed at regular intervals through September 1992. Measurements at diagnosis included hemodynamic and pulmonary function variables in addition to information on demographic data and medical history. The response to vasodilator treatment was also analyzed. The estimated median survival of the group was 4.04 years (95% confidence interval, 2.98 to 5.08 years). Variables associated with poor survival (univariate analysis) included an elevated mean right atrial pressure, a decreased cardiac index, and a decreased mixed venous PO2. A reduced forced vital capacity and the absence of vasodilator treatment were also associated with poor survival. A multivariate Cox proportional-hazards regression analysis was used to assess the adjusted hazard ratios, hence the relative contributions of the variables controlling for confounding. Reduced forced vital capacity and cardiac index and increased right atrial pressure were still significantly associated as risk factors for survival in patients with PPH. Survival as computed by the equation correlated with real survival of PPH patients with positive predictive values of 87%, 91%, and 89% at 1, 2, and 3 years, respectively. The equation, however, was relatively unable to predict deaths in our population, in part because of the strict limits of poor prognosis. Mortality in PPH is largely associated with hemodynamic variables that assess right ventricular function. The proposed prognostic equation had a high sensitivity and a relatively low specificity to predict survival in our PPH population. To improve this specificity it may be necessary to increase the limits of poor prognosis as defined by the equation.