Self-monitoring of Blood Pressure in Patients With Hypertension-Related Multi-morbidity: Systematic Review and Individual Patient Data Meta-analysis

BACKGROUND

Studies have shown that self-monitoring of blood pressure (BP) is effective when combined with co-interventions, but its efficacy varies in the presence of some co-morbidities. This study examined whether self-monitoring can reduce clinic BP in patients with hypertension-related co-morbidity.

METHODS

A systematic review was conducted of articles published in Medline, Embase, and the Cochrane Library up to January 2018. Randomized controlled trials of self-monitoring of BP were selected and individual patient data (IPD) were requested. Contributing studies were prospectively categorized by whether they examined a low/high-intensity co-intervention. Change in BP and likelihood of uncontrolled BP at 12 months were examined according to number and type of hypertension-related co-morbidity in a one-stage IPD meta-analysis.

RESULTS

A total of 22 trials were eligible, 16 of which were able to provide IPD for the primary outcome, including 6,522 (89%) participants with follow-up data. Self-monitoring was associated with reduced clinic systolic BP compared to usual care at 12-month follow-up, regardless of the number of hypertension-related co-morbidities (−3.12 mm Hg, [95% confidence intervals −4.78, −1.46 mm Hg]; P value for interaction with number of morbidities = 0.260). Intense interventions were more effective than low-intensity interventions in patients with obesity (P < 0.001 for all outcomes), and possibly stroke (P < 0.004 for BP control outcome only), but this effect was not observed in patients with coronary heart disease, diabetes, or chronic kidney disease.

CONCLUSIONS

Self-monitoring lowers BP regardless of the number of hypertension-related co-morbidities, but may only be effective in conditions such obesity or stroke when combined with high-intensity co-interventions.

Bail-out rotational atherectomy to ablate stent struts after treatment of a LAD bifurcation lesion with the Trousers technique

We present a previously unreported complication of the "trousers" stent procedure used for treatment of a bifurcation lesion in the left anterior descending artery and the first diagonal branch. Closure of the main vessel occurred. A balloon, however, could not be advanced across the side-branch stent to open the struts toward the main branch. Therefore, a bailout rotational atherectomy was performed to ablate the stent that then allowed a further dilatation with a PTCA balloon. This procedure resolved a potentially lethal outcome for the patient who subsequently underwent uneventful coronary by-pass grafting.

Signal-averaged electrocardiography and Doppler echocardiographic study in predicting acute rejection in heart transplantation

BACKGROUND AND METHODS

In a prospective protocol for noninvasive diagnosis of acute cardiac rejection, 83 routine endomyocardial biopsies, followed each time by the analysis of signal-averaged electrocardiography and by a cardiac Doppler echocardiographic study, were performed in 18 heart transplant recipients. The follow-up time was 5 +/- 3.6 months. To detect noninvasively acute cardiac rejection, we compared biopsy findings with the presence of late potentials at signal-averaged electrocardiography and with two diastolic indexes, pressure half-time, and isovolumic relaxation time obtained from Doppler echocardiographic study.

RESULTS

Thirteen acute rejection crises requiring modification of immunosuppression were diagnosed by means of endomyocardial biopsy. This clinically relevant acute cardiac rejection was associated with the presence of late potentials in 69% of cases and with the presence of pressure half-time < or = 55 msec and isovolumic relaxation time < or = 60 msec in 69% and 62% of cases, respectively. Sensitivity and specificity were as follows: for late potentials, 69% and 71%; for pressure half-time < or = 55 msec, 69% and 76%; for isovolumic relaxation time < or = 60 msec, 62% and 83%, respectively. The presence in a single patient of at least one abnormal parameter showed a sensitivity of 100% and a specificity of 60% in detecting important rejection.

CONCLUSIONS

These data support the use of combined signal-averaged electrocardiography and Doppler echocardiographic study of the left ventricular diastolic function in the screening of acute cardiac rejection. Such results can suggest when endomyocardial biopsy should be performed, with the reliance that a normal noninvasive study highly excludes the presence of acute cardiac rejection requiring intensified immunosuppression.

Serum sialic acid, a risk factor for cardiovascular disease, is increased in IDDM patients with microalbuminuria and clinical proteinuria

OBJECTIVE

An elevated serum sialic acid concentration has recently been shown to be a potent cardiovascular risk factor in the general population. Because clinical proteinuria is associated with a high frequency of cardiovascular disease, and because microalbuminuria predicts the development of renal and cardiovascular disease in diabetes, we investigated whether serum sialic acid levels are increased in insulin-dependent diabetes mellitus (IDDM) patients with microalbuminuria or clinical proteinuria.

RESEARCH DESIGN AND METHODS

We studied 23 patients with IDDM who had a normal urinary albumin excretion rate, 23 patients who had microalbuminuria, and 23 patients with clinical proteinuria. The patients were matched for age, sex, duration of diabetes, GHb levels, and body mass index (BMI). Fasting blood samples were taken for measurement of sialic acid, cholesterol, triglyceride, creatinine, and GHb.

RESULTS

Serum sialic acid was significantly higher in the microalbuminuric patients compared with the normoalbuminuric group (mean +/- SD: 1.93 +/- 0.26 vs. 1.76 +/- 0.27 mM, P < 0.01). Moreover, serum sialic acid was also significantly higher in the group with clinical proteinuria compared with the microalbuminuric patients (2.34 +/- 0.24 vs. 1.93 +/- 0.26 mM, P < 0.001). Serum sialic acid was not related independently to age, BMI, diabetes duration, GHb, blood pressure, serum cholesterol, triglyceride, or creatinine concentration in any of the diabetic groups.

CONCLUSIONS

These observations suggest that the serum sialic acid concentration is raised in IDDM patients with both microalbuminuria and clinical proteinuria and may play a role as a cardiovascular risk factor or disease marker in these conditions.

Familial, hemodynamic and metabolic factors in the predisposition to diabetic kidney disease

Proteinuric diabetic patients have an increased risk of cardiovascular disease and almost always have hypertension. In the early stages of diabetic renal disease (microalbuminuria) when renal function is well preserved, systemic arterial blood pressure is already elevated compared to insulin-dependent diabetic patients without microalbuminuria. Prospective studies have shown that normoalbuminuric patients who progress to microalbuminuria have higher blood pressures (albeit within the normal range) than those who persistently remain normoalbuminuric. Parents of insulin-dependent diabetic patients with nephropathy have a higher prevalence of hypertension and cardiovascular disease compared to those of patients without nephropathy. Moreover, diabetic nephropathy clusters within families. Erythrocyte sodium-lithium countertransport activity, the most consistent marker for essential hypertension and its cardiorenal complications, is elevated in diabetic patients with nephropathy and in their non-diabetic parents. These data suggest that a familial predisposition to arterial hypertension and cardiovascular disease increases the risk for the development of nephropathy and its associated cardiovascular complications in insulin-dependent diabetes. Arterial hypertension is a state of insulin resistance and diabetic patients susceptible to nephropathy have been found to be less insulin sensitive. Preventive strategies of diabetic kidney disease in the future will have to take into account its metabolic hemodynamic and familial basis.

Glucose-induced changes in renal haemodynamics in proteinuric type 1 (insulin-dependent) diabetic patients: inhibition by acetylsalicilic acid infusion

The effect of hyperglycaemia on renal function in diabetic nephropathy remains poorly understood. We investigated the renal haemodynamic response to an acute plasma glucose rise from sustained euglycaemia to sustained hyperglycaemia in eight persistently proteinuric Type 1 (insulin-dependent) diabetic patients. Studies were performed in a double-blind cross-over manner after i.v. injection of 450 mg lysine acetylsalicilate (equivalent to 250 mg acetylsalicilic acid) or equal volume of 0.9% NaCl (isotonic saline). In the isotonic saline experiments hyperglycaemia produced a significant rise, by approximately 35%, in glomerular filtration rate in all patients from 41.5 +/- 5.2 to 55 +/- 6 ml.min-1.1.73 m-2 (p < 0.005) and an increase in sodium paraminohippurate clearance from 178 +/- 22.7 to 220 +/- 20.0 ml.min-1.1.73 m-2 (p < 0.05). These changes took place within the first 30 min of glucose infusion and were maintained for a 90 min hyperglycaemic period. Filtration fraction did not change significantly. Infusion of lysine acetylsalicilate lowered baseline glomerular filtration rate (isotonic saline vs lysine acetylsalicilate 41.5 +/- 5.2 vs 30.0 +/- 5.7 ml.min-1.1.73 m-2; p < 0.05) and significantly blunted the rise in glomerular filtration rate during hyperglycaemia (glomerular filtration rate increment: saline vs lysine acetylsalicilate: 13.6 +/- 2.8 vs 5.3 +/- 1.8 ml.min-1.1.73 m-2; p < 0.005). The effects on renal plasma flow were similarly blunted. In five additional patients, time- and volume-controlled isotonic saline experiments during sustained euglycaemia showed no significant changes in glomerular filtration rate and sodium paraminohippurate clearance.(ABSTRACT TRUNCATED AT 250 WORDS)

Predisposition to essential hypertension and the development of diabetic nephropathy

Only a subset of insulin-dependent diabetic patients are at risk of developing nephropathy. Prospective studies of uncomplicated insulin-dependent diabetic cohorts have shown that a rise in systemic arterial pressure is a concomitant feature of the progression to early nephropathy. The development of hypertension is an integral feature of established nephropathy in diabetes, and its amelioration retards the progression of disease and may improve overall mortality. Family studies have suggested that nondiabetic parents of insulin-dependent diabetic patients with nephropathy have a greater prevalence of hypertension, and in certain groups of non-insulin dependent patients, it has been found that the blood pressure before the onset of diabetes correlates with the development of nephropathy after the onset of diabetes. These results indicate that a propensity to hypertension may be part of the genetic predisposition to nephropathy. This contention is further supported by the finding that a raised erythrocyte sodium-lithium countertransport, a biochemical marker of hypertension and cardiovascular disease whose activity is largely genetically determined, occurs with greater frequency in proteinuric diabetic patients and their nondiabetic parents than in those diabetic patients without nephropathy and their parents. Recent family studies have also shown that a family history of cardiovascular disease significantly increases the risk of nephropathy by up to three-fold in insulin-dependent diabetes. It is suggested that the cardiorenal complications of diabetes mellitus may be linked to reduced insulin sensitivity, which itself is associated with hypertension, raised sodium-lithium countertransport rates, and cardiovascular disease.

Na+/H+ antiport activity and cell growth in cultured skin fibroblasts of IDDM patients with nephropathy

IDDM patients with incipient and overt nephropathy have been found to exhibit an overactivity of RBC sodium-lithium countertransport. To explore the physiological relevance of this finding, we measured the activity of Na+/H+ antiport in serially passaged cultured skin fibroblasts from IDDM patients with and without nephropathy and from normal, nondiabetic control subjects. Na+/H+ antiport activity (measured as the rate of amiloride-sensitive Na+ influx at pHi = 6.4, extracellular pH = 8.0, and [Na+] = 1 mM) was elevated significantly in IDDM patients with nephropathy compared with IDDM patients without nephropathy and nondiabetic control subjects (13.35 +/- 3.8 vs. 8.54 +/- 2.0 vs. 7.33 +/- 2.3 nmol Na+.mg protein-1.min-1; P less than 0.006 and P less than 0.001, respectively). A kinetic analysis of Na+/H+ antiport activity showed that the raised activity in IDDM patients with nephropathy was caused by an increased Vmax for extracellular Na+. Km values were similar in the three groups. pH-stimulated amiloride-sensitive Na+ influx also was higher under baseline conditions and after serum stimulation in cells from IDDM patients with nephropathy. pHi values were significantly higher, both during active proliferation and after 10-min exposure to serum, in cells from IDDM patients with nephropathy, compared with IDDM patients without nephropathy and nondiabetic control subjects. Serum-stimulated incorporation of [3H]thymidine into DNA was greater in IDDM patients with nephropathy than in the other two groups (35.7 +/- 18.9- vs. 17.4 +/- 7.5- vs. 11.9 +/- 8.7-fold stimulation above baseline; P less than 0.01 for both.(ABSTRACT TRUNCATED AT 250 WORDS)

Familial clustering of cardiovascular disease in patients with insulin-dependent diabetes and nephropathy

BACKGROUND

Patients who have insulin-dependent diabetes mellitus and nephropathy have an excess of cardiovascular disease. Familial factors may in part account for this phenomenon.

METHODS

We identified 61 white patients under 65 years of age with insulin-dependent diabetes who had nephropathy, and then matched them with 61 diabetic patients without nephropathy. We determined the prevalence of cardiovascular disease in the parents of these patients with use of information obtained from death certificates or from the World Health Organization questionnaire for cardiovascular disease.

RESULTS

The rates of ascertainment of information were 96 percent (n = 117) for the parents of diabetic patients with nephropathy and 95 percent (n = 116) for the parents of patients without nephropathy. Cardiovascular disease was more often a direct cause of death among the parents of diabetic patients with nephropathy (40 percent vs. 22 percent, P less than 0.03), and the combined morbidity and mortality from cardiovascular disease in this group was greater than that in the parents of diabetic patients without nephropathy (31 percent vs. 14 percent, P less than 0.01). The age-adjusted and sex-adjusted relative risk of cardiovascular disease in this group of parents was 2.9 (95 percent confidence interval, 1.5 to 5.5; P less than 0.001). Moreover, a paternal history of cardiovascular disease was associated with a significantly increased risk of nephropathy in the diabetic patient after the analysis was adjusted for age, sex, and duration of diabetes (odds ratio, 3.2; 95 percent confidence interval, 1.3 to 7.9; P less than 0.01). Among the diabetic patients with nephropathy, those who had had a cardiovascular event were much more likely to have a family history of cardiovascular disease (odds ratio, 6.2; 95 percent confidence interval, 2.0 to 19.0; P less than 0.005) than those who had not had such an event.

CONCLUSIONS

Among patients with insulin-dependent diabetes, a parental history of cardiovascular disease is significantly associated with the development of nephropathy and, among those with nephropathy, increases the likelihood of cardiovascular disease.

Diagnostic sensitivity bias -- an epidemiologic explanation for an apparent brain tumor excess

Preliminary data showing over-representation of the Eastman Kodak Company (Rochester) on death certificates of brain tumor patients, and higher risk for older workers when compared to the general population, led to a case-control epidemiologic study. Chemical exposure histories of 56 workers with brain tumors were compared with those of other Kodak employees. No differences were found in exposure to a variety of chemicals. In addition, employees with brain tumors were compared to other upstate New York brain tumor patients; there was no difference in histology. However, the Kodak employees had diagnoses more frequently confirmed by histologic examination and more thorough diagnostic studies. Thus, the apparent initial excess of diagnosed tumors may have resulted from a "diagnostic sensitivity bias" arising from more complete medical evaluation of Kodak employees.

Vein of Galen ligation in the primate. Angiographic, gross, and light microscopic evaluation

✓ The vein of Galen was ligated in 16 Rhesus monkeys and six mongrel dogs, and the animals followed for periods up to six months. Ventricular size was determined preoperatively by pneumoencephalography. Angiography was performed prior to surgery and at intervals from the immediate postoperative period to 6 months following vein ligation. After sacrifice, all brains were serially sectioned and examined by light microscopy. In no case was hydrocephalus found to follow vein of Galen ligation. Consequences were limited to angiographic dilatation of major draining sinuses and cortical veins and microscopic dilatation of diencephalic and choroidal vessels. These changes were evident in the immediate postoperative period and persisted for as long as the animals were followed.