Burden of hospitalization in clinically diagnosed peripheral artery disease: A community-based study.

The burden and predictors of hospitalization over time in community-based patients with peripheral artery disease (PAD) have not been established. This study evaluates the frequency, reasons and predictors of hospitalization over time in community-based patients with PAD. We assembled an inception cohort of 1798 PAD cases from Olmsted County, MN, USA (mean age 71.2 years, 44% female) from 1 January 1998 through 31 December 2011 who were followed until 2014. Two age- and sex-matched controls ( n = 3596) were identified for each case. ICD-9 codes were used to ascertain the primary reasons for hospitalization. Patients were censored at death or last follow-up. The most frequent reasons for hospitalization were non-cardiovascular: 68% of 8706 hospitalizations in cases and 78% of 8005 hospitalizations in controls. A total of 1533 (85%) cases and 2286 (64%) controls ( p < 0.001) were hospitalized at least once; 1262 (70%) cases and 1588 (44%) controls ( p < 0.001) ≥ two times. In adjusted models, age, prior hospitalization and comorbid conditions were independently associated with increased risk of recurrent hospitalizations in both groups. In cases, severe PAD (ankle-brachial index < 0.5) (HR: 1.25; 95% CI: 1.15, 1.36) and poorly compressible arteries (HR: 1.26; 95% CI: 1.16, 1.38) were each associated with increased risk for recurrent hospitalization. We demonstrate an increased rate of hospitalization in community-based patients with PAD and identify predictors of recurrent hospitalizations. These observations may inform strategies to reduce the burden of hospitalization of PAD patients.

Frequency, Predictors, and Implications of Abnormal Blood Pressure Responses During Dobutamine Stress Echocardiography.

BACKGROUND: It is not known whether abnormal blood pressure (BP) responses during dobutamine stress echocardiography (DSE) are associated with abnormal test results, nor if such results indicate obstructive coronary artery disease (CAD). We sought to define the frequency of abnormal BP responses during DSE and their impact on accuracy of test results. METHODS AND RESULTS: We studied 21 949 patients who underwent DSE at Mayo Clinic, Rochester, MN, grouped by peak systolic BP achieved during the test. We also analyzed a subgroup who underwent coronary angiography within 30 days after positive DSE. The positive predictive value of DSE was calculated for each BP group. Patients with hypertensive response (n=1905; 9%) were more likely to have positive DSE than those with normal (n=19 770; 90%) or hypotensive (n=274; 1%) BP responses (32% versus 21% versus 23%, respectively; P<0.0001). Angiography, performed in 1126 patients, showed obstructive CAD (≥50% stenosis) in 814 patients and severe CAD (≥70% stenosis) in 708 patients. Positive predictive value of DSE was similar for patients who had hypertensive and normal BP responses (69% versus 73%; P=0.3), considering 50% stenosis cut point. The proportion of severe CAD (≥70% stenosis) was lower in patients who had hypertensive response compared with those who had normal BP response (54% versus 65%; P=0.005). CONCLUSIONS: Patients with hypertensive response during DSE are more likely to have stress-induced myocardial ischemia compared with those with normal or hypotensive BP responses but are not more likely to have false-positive DSE results. They are, however, less likely to have higher grade or multivessel CAD.

Mining peripheral arterial disease cases from narrative clinical notes using natural language processing.

OBJECTIVE: Lower extremity peripheral arterial disease (PAD) is highly prevalent and affects millions of individuals worldwide. We developed a natural language processing (NLP) system for automated ascertainment of PAD cases from clinical narrative notes and compared the performance of the NLP algorithm with billing code algorithms, using ankle-brachial index test results as the gold standard. METHODS: We compared the performance of the NLP algorithm to (1) results of gold standard ankle-brachial index; (2) previously validated algorithms based on relevant International Classification of Diseases, Ninth Revision diagnostic codes (simple model); and (3) a combination of International Classification of Diseases, Ninth Revision codes with procedural codes (full model). A dataset of 1569 patients with PAD and controls was randomly divided into training (n = 935) and testing (n = 634) subsets. RESULTS: We iteratively refined the NLP algorithm in the training set including narrative note sections, note types, and service types, to maximize its accuracy. In the testing dataset, when compared with both simple and full models, the NLP algorithm had better accuracy (NLP, 91.8%; full model, 81.8%; simple model, 83%; P < .001), positive predictive value (NLP, 92.9%; full model, 74.3%; simple model, 79.9%; P < .001), and specificity (NLP, 92.5%; full model, 64.2%; simple model, 75.9%; P < .001). CONCLUSIONS: A knowledge-driven NLP algorithm for automatic ascertainment of PAD cases from clinical notes had greater accuracy than billing code algorithms. Our findings highlight the potential of NLP tools for rapid and efficient ascertainment of PAD cases from electronic health records to facilitate clinical investigation and eventually improve care by clinical decision support.

Typical blood pressure response during dobutamine stress echocardiography of patients without known cardiovascular disease who have normal stress echocardiograms.

AIMS: Blood pressure (BP) responses during dobutamine stress echocardiography (DSE) have not been systematically studied. Consequently, it is not known what constitutes a normal or an abnormal BP response to dobutamine stress. We sought to define the typical BP response during DSE of patients not known to have cardiovascular disease. METHODS AND RESULTS: Of 24 134 patients who underwent DSE from November 2003 to December 2012 at Mayo Clinic, Rochester, MN, 2968 were selected for inclusion in this retrospective study. Excluded were patients with a history of hypertension, diabetes, or coronary artery disease, and those taking vasoactive medications. Patients who had baseline and/or stress-induced wall motion abnormalities were also excluded. The distribution of the study population's BP responses during DSE was Gaussian; we defined cut-point values for normative BP responses at 2 SD for each decade of age and for the whole study population. During DSE, systolic BP (SBP) increased from baseline to peak stress (Δ +2.9 ± 24 mmHg, P < 0.0001) and diastolic BP (DBP) decreased (Δ -7.4 ± 14 mmHg). BP changes were age and sex dependent; men and younger patients had greater ΔSBP and lesser ΔDBP, compared with women and older patients. Patients who received atropine had higher peak BP values than patients who did not receive atropine, due to greater ΔSBP (+7.4 ± 26 vs. -0.5 ± 22 mmHg, P < 0.0001) and lesser ΔDBP (-4 ± 14 vs. -9.7 ± 12 mmHg, P < 0.0001). This atropine effect was present in men and women, and was more pronounced in younger patients. The normative peak SBP values ranged from 82 to 182 mmHg. CONCLUSION: BP responses during DSE vary and depend on patients' age, gender, and the use of atropine. We describe the typical BP responses seen during DSE and report normative reference values, which can be used for defining normal and abnormal BP responses to dobutamine stress.

Identifying Peripheral Arterial Disease Cases Using Natural Language Processing of Clinical Notes.

Peripheral arterial disease (PAD) is a chronic disease that affects millions of people worldwide. Ascertaining PAD status from clinical notes by manual chart review is labor intensive and time consuming. In this paper, we describe a natural language processing (NLP) algorithm for automated ascertainment of PAD status from clinical notes using predetermined criteria. We developed and evaluated our system against a gold standard that was created by medical experts based on manual chart review. Our system ascertained PAD status from clinical notes with high sensitivity (0.96), positive predictive value (0.92), negative predictive value (0.99) and specificity (0.98). NLP approaches can be used for rapid, efficient and automated ascertainment of PAD cases with implications for patient care and epidemiologic research.

Echocardiographic abnormalities in the assessment of cardiac organ damage in never-treated hypertensive patients.

Hypertension-related cardiac organ damage, other than left ventricular (LV) hypertrophy (LVH), has been described: in particular, concentric remodeling, LV diastolic dysfunction (DD), and left atrial (LA) enlargement are significantly associated with cardiovascular morbility and mortality in different populations. This study evaluated the prevalence of these latter morphofunctional abnormalities, in never-treated essential hypertensive patients and the role of such a serial assessment of hypertensive cardiac damage in improving cardiovascular risk stratification in these patients. A total of 100 never-treated essential hypertensive subjects underwent a complete clinical and echocardiographic evaluation. Left ventricular morphology, systolic and diastolic function, and LA dimension (linear and volume) were evaluated by echocardiography. Left ventricular hypertrophy was present in 14% of the patients, whereas concentric remodeling was present in 25% of the subjects. Among patients free from LV morphology abnormalities, the most frequent abnormality was LA enlargement (global prevalence 57%); the percentage of patients with at least one parameter consistent with DD was 22% in the entire population, but DD was present as the only cardiac abnormality in 1% of our patient. Left atrial volume indexed for body surface area was the most sensitive parameter in identifying hypertension-related cardiac modification. The global prevalence of cardiac alteration reached 73% in never-treated hypertensive patients. Left ventricular remodeling and LA enlargement evaluation may grant a better assessment of cardiac organ damage and cardiovascular risk stratification of hypertensive patients without evidence of LVH after routine examination.

Left atrial enlargement in essential hypertension: role in the assessment of subclinical hypertensive heart disease.

BACKGROUND: Arterial hypertension is a common cause of cardiac organ damage, inducing morphofunctional modifications involving left chambers. This is a retrospective study: it was designed to evaluate the additive clinical value of left atrial enlargement (LAe) assessment in the evaluation of cardiac organ damage. METHODS: A total of 814 (67% male; aged 50.7 ± 12 years, mean ± SD) essential hypertensive subjects underwent routinely to a complete and extensive clinical and echocardiographic evaluation. Left ventricular morphology, systolic and diastolic function and left atrial dimension (LAD; linear and volumetric) were evaluated. RESULTS: Prevalence of LAe varied between 6.2% and 52.1%, depending on the chosen criteria (left atrial diameter indexed for body surface area (BSA) vs left atrial volume (LAV) indexed for BSA - LAVi). LAVi showed to be the most sensitive parameter in order to detect it (sensitivity 96%, specificity 100%). Left ventricular hypertrophy (LVH) was present in about one fifth of our population (14% and 26%, considering indexation for BSA and for height(2.7)). Concentric remodelling (CR) was present in 27-35% of cases considering left ventricular mass indexation for BSA and for height(2.7), respectively. In one quarter of our population, LAe was the only echocardiographic sign of hypertension, independent of LVH and CR. CONCLUSIONS: LAV evaluation in hypertensive population can contribute to the identification of subjects affected by hypertensive heart disease other than the conventionally evaluated terms (LVH and CR).

Anti-hypertensive drugs and left ventricular hypertrophy: a clinical update.

Structural remodelling of the heart, known as left ventricular hypertrophy (LVH), is a consequence of systemic hypertension, and is associated with an increased risk of cardiovascular morbidity and mortality. Therefore, particular attention should be paid to the identification, prevention and treatment of this condition in hypertensive patients. LVH seems to benefit from all classes of anti-hypertensive drugs; however, antagonists of the renin-angiotensin-aldosterone system (RAAS) have demonstrated an additional benefit in the inhibition and reversal of myocardial interstitial fibrosis. Nevertheless, in evaluating the degree of arterial hypertension and organ damage, many neuro-hormonal systems are involved, primarily the sympathetic nervous system, thereby explaining the use of different classes of anti-hypertensive drugs to prevent or reduce LVH. The RAAS antagonists are actually the recommended anti-hypertensive agents to prevent organ damage in hypertensive subjects or in hypertensives with evidence of LVH to reduce cardiovascular mortality and morbidity.

Efficacy of antihypertensive treatment based on plasma renin activity: An open label observational study.

BACKGROUND: We investigated the extent of blood pressure (BP) reduction and control (<140/90 mmHg) in patients treated with appropriate or inappropriate drugs according to their plasma renin activity (PRA) level (natriuretic drugs and renin-angiotensin system blockers for low-renin and high-renin hypertension, respectively). PATIENTS AND METHODS: One hundred and seventy Caucasian untreated hypertensive patients (61 females), aged 18-70 years, participated to the study. Patients with secondary hypertension, diabetes or established cardiovascular or renal disease were excluded. The physician prescribed an antihypertensive monotherapy chosen among all drug classes, unaware of patient's PRA levels. We compared effect of an inappropriate or appropriate drug, evaluating BP values after a month of treatment. RESULTS: Rate of BP control was not significantly higher in patients treated with an appropriate drug than the others (38% vs 29%, p=0.24). However, in a regression analysis, final diastolic BP (DBP) was lower in subjects treated with an appropriate drug (beta=-2.84, p=0.03). CONCLUSIONS: The present study does not clearly support the use of PRA in a general population of hypertensive patients to optimize BP control. However, the greater efficacy of a drug appropriate to PRA in reducing DBP may be clinically helpful in young hypertensive patients. Future studies are warranted to evaluate if PRA determination enhances the therapeutic success in patients with predominantly high values of DBP.